Finnish (suomi , or suomen kieli [ˈsuo̯meŋ ˈkie̯li]) is a Uralic language of the Finnic branch spoken by the majority of the population in Finland and by ethnic Finns outside Finland. Finnish, along with Swedish, is an official languages of Finland; Finnish is also an official minority language in Sweden. In Sweden, both Standard Finnish and Meänkieli, its own language or a dialect of Finnish, are spoken. The Kven language, a dialect of Finnish or even a distinct language, is spoken in Northern Norway by a minority group of Finnish descent. The status of kven and meänkieli are debated.

Finnish is a member of the Finnic language family and is typologically between fusional and agglutinative languages. It modifies and inflects nouns, adjectives, pronouns, numerals and verbs, depending on their roles in the sentence.

Finnish is a member of the Finnic group of the Uralic family of languages. The Finnic group also includes Estonian and a few minority languages spoken around the Baltic Sea.

Finnish demonstrates an affiliation with other Uralic languages (such as Hungarian) in several respects including:

Several theories exist as to the geographic origin of Finnish and the other Uralic languages. The most widely held view is that they originated as a Proto-Uralic language somewhere in the boreal forest belt around the Ural Mountains region and/or the bend of the middle Volga. The strong case for Proto-Uralic is supported by common vocabulary with regularities in sound correspondences, as well as by the fact that the Uralic languages have many similarities in structure and grammar.^[8]

The Defense Language Institute in Monterey, California, United States classifies Finnish as a level III language (of 4 levels) in terms of learning difficulty for native English speakers.^[9]

Finnish is spoken by about five million people, most of whom reside in Finland. There are also notable Finnish-speaking minorities in Sweden, Norway, Russia, Estonia, Brazil, Canada, and the United States. The majority of the population of Finland, 90.37% as of 2010, speak Finnish as their first language.^[10] The remainder speak Swedish (5.42%),^[10] Sami (Northern, Inari, Skolt) and other languages. It is spoken as a second language in Estonia by about 167,000 people.^[11]

Finnish is one of two official languages of Finland (the other being Swedish, spoken by 5.42% of the population as of 2010^[10]) and one of the official languages in the European Union since 1995. Finnish language started to gain its role during the Grand Duchy of Finland, along with the nationalistic Fennoman movement, and obtained its official status in the Finnish Diet of 1863. It enjoys the status of an official minority language in Sweden. Under the Nordic Language Convention, citizens of the Nordic countries speaking Finnish have the opportunity to use their native language when interacting with official bodies in other Nordic countries without being liable to any interpretation or translation costs.^[12][13] Concerns have been expressed about future status of Finnish language in Sweden.^[14]

The Finnic languages evolved from the Proto-Finnic language after Sámi was separated from it around 1500–1000 BCE.^[15] Current models assume three or more hypothetical Proto-Finnic proto-dialects evolving over the first millennium BCE.^[16]

Birch bark letter 292 from the early 13th century is the first known document in any Finnic language. The first known written example of Finnish was found in a German travel journal dating back to c.1450: Mÿnna tachton gernast spuho somen gelen emÿna daÿda (Modern Finnish: "Minä tahdon kernaasti puhua suomen kieltä, [mutta] en minä taida;" English: "I want to speak Finnish, [but] I am not able").^[17] According to the travel journal, a Finnish bishop, whose name is unknown, was behind the above quotation. The contextually erroneous accusative case in gelen (Finnish kielen) and the lack of the conjunction mutta seem to indicate a foreign speaker with an incomplete grasp of Finnish grammar, as errors with the numerous noun cases are typical of those learning Finnish.^[18] Finnish priestdom at the time was largely Swedish-speaking.^[19]

During the Middle Ages, when Finland was under Swedish rule, Finnish was solely an oral language. At the time the language of large-scale business was Middle Low German, the language of administration Swedish, and religious activities were held in Latin. This left few possibilities for Finnish-speakers to use their mother tongue in situations other than daily chores. From a Swedish perspective, Finnish was considered an inferior language and in practice Finns lacked societal rights because they could not represent themselves in any official situation with their language. Swedes strove to obviate Finnish via clerk schools and Church service, and by moving Swedish-speaking people to Finnish-speaking areas.^[20]

The first comprehensive writing system for Finnish was created by Mikael Agricola, a Finnish bishop, in the 16th century. He based his orthography on Swedish, German, and Latin. His ultimate plan was to translate the Bible, but first he had to define rules on which the Finnish standard language still relies, particularly with respect to spelling.

Agricola's written language was based on western dialects of Finnish, and his intention was that each phoneme should correspond to one letter. Yet, Agricola was confronted with many problems in this endeavour and failed to achieve uniformity. This is why he might use different signs for the same phonemes depending on the situation. For example, he used dh or d to represent the voiced dental fricative /ð/ (English th in this) and tz or z to represent the geminate voiceless dental fricative /θ/ (the th in thin). Additionally, Agricola might use gh or g to represent the voiced velar fricative /ɣ/ and either ch, c or h for /h/. For example, he wrote techtin against modern spelling tehtiin.

Others revised Agricola's work later, striving for a more phonemic system. Along the way, Finnish lost some of its phonemes. The sounds /ð/ and /θ/ disappeared from the standard language, surviving only in a small rural region in Western Finland.^[21] Elsewhere, traces of these phonemes persist as their disappearance gave Finnish dialects their distinct qualities. For example, /θ/ became ht or tt (e.g. meþþä → mehtä, mettä) in the eastern dialects and in some western dialects. In the standard language, however, the effect of the lost phonemes is thus:

Modern Finnish punctuation, along with that of Swedish, uses the colon character to separate the stem of the word and its grammatical ending in some cases (such as after abbreviations), where some other alphabetic writing systems would use an apostrophe. Suffixes are required for correct grammar, so this is often applied, e.g. EU:ssa "in the EU".

In the 19th century Johan Vilhelm Snellman and others began to stress the need to improve the status of Finnish. Ever since the days of Mikael Agricola, written Finnish had been used almost exclusively in religious contexts, but now Snellman's Hegelian nationalistic ideas of Finnish as a fully-fledged national language gained considerable support. Concerted efforts were made to improve the status of the language and to modernize it, and by the end of the century Finnish had become a language of administration, journalism, literature, and science in Finland, along with Swedish.

The most important contributions to improving the status of Finnish were made by Elias Lönnrot. His impact on the development of modern vocabulary in Finnish was particularly important. In addition to compiling the Kalevala, he acted as an arbiter in disputes about the development of standard Finnish between the proponents of western and eastern dialects, ensuring that the western dialects Agricola had preferred preserved their preeminent role, while many originally dialect words from Eastern Finland were introduced to the standard language, enriching it considerably.^[22] The first novel written in Finnish (and by a Finnish speaker) was Seven Brothers (Seitsemän veljestä), published by Aleksis Kivi in 1870.

The Finnish language has been changing in certain ways after World War II, as observed in the spreading of certain dialectal features (for example the spread of Western allophone of the cluster ts (mettä: mettän/metän (forest: forest's) instead of metsä) and the Eastern disappearance of d-sound (tiän/tiij(j)än ((i) know)) instead of the Western allophones) and the simultaneous preference to abandon the more visible dialectal features. Some scientists have also reported the moving of the ä-sound towards the a-sound, even theorising that the Finnish speakers would start to pronounce the a-sound even more distantly from the changing ä-sound in order to preserve vowel harmony.

The dialects of Finnish are divided into two distinct groups, Western and Eastern.^[23] The dialects are almost entirely mutually intelligible and are distinguished from each other by only minor changes in vowels, diphthongs and rhythm. For the most part, the dialects operate on the same phonology, grammar and vocabulary. There are only marginal examples of sounds or grammatical constructions specific to some dialect and not found in standard Finnish. Two examples are the voiced dental fricative found in the Rauma dialect, and the Eastern exessive case.

The classification of closely related dialects spoken outside Finland is a politically sensitive issue that has been controversial since Finland's independence in 1917. This concerns specifically the Karelian language in Russia and Meänkieli in Sweden, the speakers of which are often considered oppressed minorities. Karelian is different enough from standard Finnish to have its own orthography. Meänkieli is a northern dialect altmost entirely intelligible to speakers of any other Finnish dialect, which achieved its status as an official minority language in Sweden for historical and political reasons, although Finnish is an official minority language in Sweden, too.in 1980 many texts books and the bible were translated into meänkieli and meänkieli has been developing more into its own language.^[24]

The Southwestern dialects (lounaismurteet) are spoken in Southwest Finland and Satakunta. Their typical feature is abbreviation of word-final vowels, and in many respects they resemble Estonian. The Tavastian dialects (hämäläismurteet) are spoken in Tavastia. They are closest to the standard language, but feature some slight vowel changes, such as the opening of diphthong-final vowels (tie → tiä, miekka → miakka, kuolisi → kualis), the change of d to l (mostly obsolete) or trilled r (widespread, nowadays disappearance of d is popular) and the personal pronouns (me:meitin (we: our), te:teitin (you:your) and he: heitin (they: their)). The Southern Ostrobothnian dialects (eteläpohjalaiset murteet) are spoken in Southern Ostrobothnia. Their most notable feature is the pronunciation of 'd' as a tapped or even fully trilled /r/. The Middle and North Ostrobothnia dialects (keski- ja pohjoispohjalaiset murteet) are spoken in Central and Northern Ostrobothnia. The Far Northern dialects (peräpohjalaiset murteet) are spoken in Lapland. The dialects spoken in the western parts of Lapland are recognizable by retention of old 'h' sounds in positions where they have disappeared from other dialects.

One of the Far Northern dialects or its own language, Meänkieli, which is spoken on the Swedish side of the border, is taught in some Swedish schools as a distinct standardized language. The speakers of Meänkieli became politically separated from the other Finns when Finland was annexed to Russia in 1809. The categorization of Meänkieli as a separate language is controversial among the some Finns, who see no linguistic criteria, only political reasons, for treating Meänkieli differently from other dialects of Finnish.^[25]

The Kven language is spoken in Finnmark and Troms, in Norway. Its speakers are descendants of Finnish emigrants to the region in the 18th and 19th centuries. Kven is an official minority language in Norway.

The Eastern dialects consist of the widespread Savonian dialects (savolaismurteet) spoken in Savo and nearby areas, and the South-Eastern dialects now spoken only in Finnish South Karelia. The South-Eastern dialects (kaakkoismurteet) were previously also spoken on the Karelian Isthmus and in Ingria. The Karelian Isthmus was evacuated during World War II and refugees were resettled all over Finland. Most Ingrian Finns were deported to various interior areas of the Soviet Union.

Palatalization, a common feature of Uralic languages, had been lost in the Finnic branch, but it has been reacquired by most of these languages, including Eastern Finnish, but not Western Finnish. In Finnish orthography, this is denoted with a 'j', e.g. vesj [vesʲ] 'water', cf. standard vesi.

The language spoken in those parts of Karelia that have not historically been under Swedish or Finnish rule is usually called the Karelian language, and it is considered to be more distant from standard Finnish than the Eastern dialects. Whether this language of Russian Karelia is a dialect of Finnish or a separate language is a matter of interpretation. However, the term "Karelian dialects" is often used colloquially for the Finnish South-Eastern dialects.

There are two main varieties of Finnish used throughout the country. One is the "standard language" (yleiskieli), and the other is the "spoken language" (puhekieli). The standard language is used in formal situations like political speeches and newscasts. Its written form, the "book language" (kirjakieli), is used in nearly all written texts, not always excluding even the dialogue of common people in popular prose. The spoken language, on the other hand, is the main variety of Finnish used in popular TV and radio shows and at workplaces, and may be preferred to a dialect in personal communication.

Standard Finnish is prescribed by the Language Office of the Research Institute for the Languages of Finland and is the language used in official communication. The Dictionary of Contemporary Finnish (Nykysuomen sanakirja 1951–61), with 201,000 entries, was a prescriptive dictionary that defined official language. An additional volume for words of foreign origin (Nykysuomen sivistyssanakirja, 30,000 entries) was published in 1991. An updated dictionary, The New Dictionary of Modern Finnish (Kielitoimiston sanakirja) was published in an electronic form in 2004 and in print in 2006. A descriptive grammar (Iso suomen kielioppi,^[27] 1,600 pages) was published in 2004. There is also an etymological dictionary, Suomen sanojen alkuperä, published in 1992–2000, and a handbook of contemporary language (Nykysuomen käsikirja), and a periodic publication, Kielikello. Standard Finnish is used in official texts and is the form of language taught in schools. Its spoken form is used in political speech, newscasts, in courts, and in other formal situations. Nearly all publishing and printed works are in standard Finnish.

The colloquial language has mostly developed naturally from earlier forms of Finnish, and spread from the main cultural and political centres. The standard language, however, has always been a consciously constructed medium for literature. It preserves grammatical patterns that have mostly vanished from the colloquial varieties and, as its main application is writing, it features complex syntactic patterns that are not easy to handle when used in speech. The colloquial language develops significantly faster, and the grammatical and phonological simplifications also include the most common pronouns and suffixes, which amount to frequent but modest differences. Some sound changes have been left out of the formal language, such as the irregularization of some common verbs by assimilation, e.g. tule- → tuu- ('come', only when the second syllable is short, so the third person singular does not contract: hän tulee 'he comes', never *hän tuu; also mene- → mee-). However, the longer forms such as tule can be used in spoken language in other forms as well.

The literary language certainly still exerts a considerable influence upon the spoken word, because illiteracy is nonexistent and many Finns are avid readers. In fact, it is still not entirely uncommon to meet people who "talk book-ish" (puhuvat kirjakieltä); it may have connotations of pedantry, exaggeration, moderation, weaseling or sarcasm (somewhat like heavy use of Latinate words in English: compare the difference between saying "There's no children I'll leave it to" and "There are no children to whom I shall leave it".). More common is the intrusion of typically literary constructions into a colloquial discourse, as a kind of quote from written Finnish. It should also be noted that it is quite common to hear book-like and polished speech on radio or TV, and the constant exposure to such language tends to lead to the adoption of such constructions even in everyday language.

A prominent example of the effect of the standard language is the development of the consonant gradation form /ts : ts/ as in metsä : metsän, as this pattern was originally (1940) found natively only in the dialects of the southern Karelian isthmus and Ingria. It has been reinforced by the spelling 'ts' for the dental fricative [θː], used earlier in some western dialects. The spelling and the pronunciation this encourages however approximate the original pronunciation, still reflected in e.g. Karelian /čč : č/ (meččä : mečän). In the spoken language, a fusion of Western /tt : tt/ (mettä : mettän) and Eastern /ht : t/ (mehtä : metän) has resulted: /tt : t/ (mettä : metän).^[28] It is notable that neither of these forms are identifiable as, or originate from, a specific dialect.

The orthography of informal language follows that of the formal. However, in signalling the former in writing, syncope and sandhi – especially internal – may occasionally amongst other characteristics be transcribed, e.g. menenpä → me(n)empä. This never occurs in the standard variety.

Note that there are noticeable differences between dialects. Also note that here the formal language does not mean a language spoken in formal occasions but the standard language which exists practically only in written form.

The phoneme inventory of Finnish is moderately large^[29], with a great number of vocalic segments and a restricted set of consonant types, both of which can be long or short.

Finnish monophthongs show eight vowels qualities that contrast in duration, thus 16 vowel phonemes in total. Allophony is restricted. Vowel phonemes are always contrastive in word-initial syllables; for noninitial syllable, see morphophonology below. Mid vowels tend to be open-mid. Long and short vowels are shown below.

The usual analysis is that Finnish has long and short vowels and consonants as distinct phonemes. However, long vowels may be analyzed as a vowel followed by a chroneme, or also, that sequences of identical vowels are pronounced as "diphthongs". The quality of long vowels mostly overlaps with the quality of short vowels, with the exception of u, which is centralized with respect to uu; long vowels do not morph into diphthongs. There are eighteen phonemic diphthongs; like vowels, diphthongs do not have significant allophony.

Finnish has a consonant inventory of small to moderate size, where voicing is mostly not distinctive, and fricatives are scarce. Finnish has relatively few non-coronal consonants. Consonants are as follows, where consonants in parenthesis are found only in a few recent loans, and may be mispronounced by uneducated speakers.

Almost all consonants have phonemic short and long (geminated) forms, although length is only constrastive in consonants word-medially.

Consonant clusters are mostly absent in native Finnish words, except for a small set of two-consonant sequences in syllable codas, e.g. 'rs' in karsta. However, because of a number of recently adopted loanwords that have them, e.g. strutsi from Swedish struts, meaning "ostrich", clusters have been integrated to the modern language to different degrees.

Finnish is somewhat divergent from other Uralic languages in two respects: it has lost most fricatives, as well as losing the distinction between palatalized and non-palatalized consonants. Finnish has only two fricatives in native words, namely /s/ and /h/. All other fricatives are recognized as foreign, of which Finnish speakers can usually reliably distinguish /f/ and /ʃ/. (The official alphabet includes 'z' [z] and 'ž' [ʒ], but these are rarely used correctly, including by the Swedish-speakers, who also struggle with those sounds.) While standard Finnish has lost palatalization, which is characteristic of Uralic languages, the Eastern dialects and the Karelian language have redeveloped or retained it. For example, the Karelian word d'uuri [dʲuːri], with a palatalized /dʲ/, is reflected by juuri in Finnish and Savo dialect vesj [vesʲ] is vesi in standard Finnish.

A feature of Finnic phonology is the development of labial and rounded vowels in non-initial syllables, as in the word tyttö. Proto-Uralic had only 'a' and 'i' and their vowel harmonic allophones in non-initial syllables; modern Finnish allows other vowels in non-initial syllables, although they are uncommon compared to 'a', 'ä' and 'i'.

Characteristic features of Finnish (common to some other Uralic languages) are vowel harmony and an agglutinative morphology; owing to the extensive use of the latter, words can be quite long.

The main stress is always on the first syllable, and it is articulated by adding approximately 100 ms more length to the stressed vowel.^[30] Stress does not cause any measurable modifications in vowel quality (very much unlike English). However, stress is not strong and words appear evenly stressed. In some cases, stress is so weak that the highest points of volume, pitch and other indicators of "articulation intensity" are not on the first syllable, although native speakers recognize the first syllable as a stressed syllable.

Finnish has several morphophonological processes that require modification of the forms of words for daily speech. The most important processes are vowel harmony and consonant gradation.

Vowel harmony is a redundancy feature, which means that the feature [±back] is uniform within a word, and so it is necessary to interpret it only once for a given word. It is meaning-distinguishing in the initial syllable, and suffixes follow; so, if the listener hears [±back] in any part of the word, they can derive [±back] for the initial syllable. For example, from the stem tuote ("product") one derives tuotteeseensa ("into his product"), where the final vowel becomes the back vowel 'a' (rather than the front vowel 'ä') because the initial syllable contains the back vowels 'uo'. This is especially notable because vowels 'a' and 'ä' are different, meaning-distinguishing phonemes, not interchangeable or allophonic. Finnish front vowels are not umlauts.

Consonant gradation is a partly nonproductive^[31] lenition process for P, T and K in inherited vocabulary, with the oblique stem "weakened" from the nominative stem, or vice versa. For example, tarkka "precise" has the oblique stem tarka-, as in tarkan "of the precise". There is also another gradation pattern, which is older, and causes simple elision of T and K in suffixes. However, it is very common since it is found in the partitive case marker: if V is a single vowel, V+ta → Va, e.g. *tarkka+ta → tarkkaa.

Finnish is a synthetic language that employs extensive regular agglutination of modifiers to verbs, nouns, adjectives and numerals. However, Finnish is not a polysynthetic language, although non-finite dependent clauses may be contracted to infinitives (lauseenvastike, e.g. juode·ssa·ni "when I was drinking", lit. "drink-in-my", that is "during my drinking").

The morphosyntactic alignment is nominative–accusative; but there are two object cases: accusative and partitive. The contrast between the two is telic, where the accusative case denotes actions completed as intended (Ammuin hirven "I shot (killed) the elk"), and the partitive case denotes incomplete actions (Ammuin hirveä "I shot (at) the elk"). Often this is confused with perfectivity, but the only element of perfectivity that exists in Finnish is that there are some perfective verbs. Transitivity is distinguished by different verbs for transitive and intransitive, e.g. ratkaista "to solve something" vs. ratketa "to solve by itself". There are several frequentative and momentane verb categories.

Verbs gain personal suffixes for each person; these suffixes are grammatically more important than pronouns, which are often not used at all in standard Finnish. The infinitive is not the uninflected form but has a suffix -ta or -da; the closest one to an uninflected form is the third person singular indicative. There are four persons, first ("I, we"), second ("you (singular), you (plural)"), third ("s/he, they"). The passive voice (sometimes called impersonal or indefinite) resembles a "fourth person" similar to, e.g., English "people say/do/...". There are four tenses, namely present, past, perfect and pluperfect; the system mirrors the Germanic system. The future tense is not needed, because of context and the telic contrast. For example, luen kirjan "I read a book (completely)" indicates a future, whereas luen kirjaa "I read a book (not yet complete)" indicates present.

Nouns may be suffixed with the markers for the aforementioned accusative case and partitive case, the genitive case, eight different locatives, and a few other cases. The case marker must be added not only to the main noun, but also to its modifiers; e.g. suure+ssa talo+ssa, literally "big-in house-in". Possession is marked with a possessive suffix; separate possessive pronouns are unknown. Pronouns gain suffixes just as nouns do.

Finnish has a smaller core vocabulary than, for example, English, and uses derivative suffixes to a greater extent. As an example, take the word kirja "a book", from which one can form derivatives kirjain "a letter" (of the alphabet), kirje "a piece of correspondence, a letter", kirjasto "a library", kirjailija "an author", kirjallisuus "literature", kirjoittaa "to write", kirjoittaja "a writer", kirjuri "a scribe, a clerk", kirjallinen "in written form", kirjata "to write down, register, record", kirjasin "a font", and many others.

Here are some of the more common such suffixes. Which of each pair is used depends on the word being suffixed in accordance with the rules of vowel harmony.

Verbal derivational suffixes are extremely diverse; several frequentatives and momentanes differentiating causative, volitional-unpredictable and anticausative are found, often combined with each other, often denoting indirection. For example, hypätä "to jump", hyppiä "to be jumping", hypeksiä "to be jumping wantonly", hypäyttää "to make someone jump once", hyppyyttää "to make someone jump repeatedly" (or "to boss someone around"), hyppyytyttää "to make someone to cause a third person to jump repeatedly", hyppyytellä "to, without aim, make someone jump repeatedly", hypähtää "to jump suddenly" (in anticausative meaning), hypellä "to jump around repeatedly", hypiskellä "to be jumping repeatedly and wantonly". Caritives are also used in such examples as hyppimättä "without jumping" and hyppelemättä "without jumping around". The diversity and compactness of both derivation and inflectional agglutination can be illustrated with istahtaisinkohan "I wonder if I should sit down for a while" (from istua, "to sit, to be seated"):

Over the course of many centuries, the Finnish language has borrowed many words from a wide variety of languages, most from neighbouring Indo-European languages. Indeed, some estimates put the core Proto-Uralic vocabulary surviving in Finnish at only around 300 word roots. Owing to the different grammatical, phonological and phonotactic structure of the Finnish language, loanwords from Indo-European have been assimilated.

In general, the first loan words into Uralic languages seem to come from very early Indo-European languages. Later important sources have been, depending on the language, Indo-Iranian, Turkic, Baltic, Germanic, and Slavic languages. Finnic languages, including Finnish, have borrowed in particular from Baltic and Germanic languages, and to a lesser extent from Slavic and Indo-Iranian languages. Furthermore, a certain group of very basic and neutral words exists in Finnish and other Finnic languages that are absent from other Uralic languages, but without a recognizable etymology from any known language. These words are usually regarded as the last remnant of the Paleo-European language spoken in Fennoscandia before the arrival of the proto-Finnic language. Words included in this group are e.g. jänis (hare), musta (black), mäki (hill), saari (island), suo (swamp) and niemi (cape (geography)).

Also some place names, like Päijänne and Imatra, are probably from before the proto-Finnic era.^[32]

Often quoted loan examples are kuningas "king" and ruhtinas "sovereign prince, high ranking nobleman" from Germanic *kuningaz and *druhtinaz—they display a remarkable tendency towards phonological conservation within the language. Another example is äiti "mother", from Gothic aiþei, which is interesting because borrowing of close-kinship vocabulary is a rare phenomenon. The original Finnish emo occurs only in restricted contexts. There are other close-kinship words that are loaned from Baltic and Germanic languages (morsian "bride", armas "dear", huora "whore"). Examples of the ancient Iranian loans are vasara "hammer" from Avestan vadžra, vajra and orja "slave" from arya, airya "man" (the latter probably via similar circumstances as slave from Slav in many European languages).

More recently, Swedish has been a prolific source of borrowings, and also, the Swedish language acted as a proxy for European words, especially those relating to government. Present-day Finland was a part of Sweden from the 12th century and was ceded to Russia in 1809, becoming an autonomous Grand Duchy. Swedish was retained as the official language and language of the upper class even after this. When Finnish was accepted as an official language, it gained legal equal status with Swedish. During the period of autonomy, Russian did not gain much ground as a language of the people or the government. Nevertheless, quite a few words were subsequently acquired from Russian (especially in older Helsinki slang) but not to the same extent as with Swedish. In all these cases, borrowing has been partly a result of geographical proximity.

Especially words dealing with administrative or modern culture came to Finnish from Swedish, sometimes reflecting the oldest Swedish form of the word (lag – laki, 'law'; län – lääni, 'province'; bisp – piispa, 'bishop'; jordpäron – peruna, 'potato'), and many more survive as informal synonyms in spoken or dialectal Finnish (e.g. likka, from Swedish flicka, 'girl', usually tyttö in Finnish).

Typical Russian loanwords are old or very old, thus hard to recognize as such, and concern everyday concepts, e.g. papu "bean", sini "(n.) blue" and pappi "priest". Notably, a few religious words such as Raamattu ("Bible") are borrowed from Russian, which indicates language contact preceding the Swedish era. This is mainly believed to be result of trade with Novgorod from the 9th century on and Russian Orthodox missions in the east in the 13th century.

Most recently, and with increasing impact, English has been the source of new loanwords in Finnish. Unlike previous geographical borrowing, the influence of English is largely cultural and reaches Finland by many routes, including international business, music, film and TV (foreign films and programmes, excluding ones intended for a very young audience, are shown subtitled), literature, and the Web – the latter is now probably the most important source of all non-face-to-face exposure to English.

The importance of English as the language of global commerce has led many non-English companies, including Finland's Nokia, to adopt English as their official operating language. Recently, it has been observed that English borrowings are also ousting previous borrowings, for example the switch from treffailla "to date" (from Swedish, träffa) to deittailla from English "to go for a date". Calques from English are also found, e.g. kovalevy (hard disk). Grammatical calques are also found, for example, the replacement of the impersonal (passiivi) with the English-style generic you, e. g. sä et voi "you cannot", instead of ei voi "one cannot". This construct, however, is limited to colloquial language, as it is against the standard grammar.

However, this does not mean that Finnish is threatened by English. Borrowing is normal language evolution, and neologisms are coined actively not only by the government, but also by the media. Moreover, Finnish and English have a considerably different grammar, phonology and phonotactics, discouraging direct borrowing. English loan words in Finnish slang include for example pleikkari "PlayStation", hodari "hot dog", and hedari "headache", "headshot" or "headbutt". Often these loanwords are distinctly identified as slang or jargon, rarely being used in a negative mood or in formal language. Since English and Finnish grammar, pronunciation and phonetics differ considerably, most loan words are inevitably sooner or later calqued – translated into native Finnish – retaining the semantic meaning.

Some modern terms have been synthesised rather than borrowed, for example:

Neologisms are actively generated by the Language Planning Office and the media. They are widely adopted. One would actually give an old-fashioned or rustic impression using forms such as kompuutteri (computer) or kalkulaattori (calculator) when the neologism is widely adopted.

Finnish is written with the Swedish variant of the Latin alphabet but with two more letters that are from some Russian loanwords. It includes the distinct characters Ä and Ö, and also several characters (b, c, f, q, w, x, z, å, š and ž) reserved for words of non-Finnish origin. The Finnish orthography follows the phoneme principle: each phoneme (meaningful sound) of the language corresponds to exactly one grapheme (independent letter), and each grapheme represents almost exactly one phoneme. This enables an easy spelling and facilitates reading and writing acquisition. The rule of thumb for Finnish orthography is: write as you read, read as you write. However, morphemes retain their spelling despite sandhi.

Some orthographical notes:

Although Finnish is almost completely written as it is spoken, there are a few differences:

When the appropriate characters are not available, the graphemes ä and ö are usually converted to a and o, respectively. This is common in e-mail addresses and other electronic media where there may be no support for characters outside the basic ASCII character set. Writing them as ae and oe, following German usage, is rarer and usually considered incorrect, but formally used in passports and equivalent situations. Both conversion rules have minimal pairs which would no longer be distinguished from each other.

The sounds š and ž are not a part of Finnish language itself and have been introduced by the Finnish national languages body for more phonologically accurate transcription of loanwords and foreign names. For technical reasons or convenience, the graphemes sh and zh are often used in quickly or less carefully written texts instead of š and ž. This is a deviation from the phonetic principle, and as such is liable to cause confusion, but the damage is minimal as the transcribed words are foreign in any case. Finnish does not use the sounds z, š or ž, but for the sake of exactitude, they can be included in spelling. (The recommendation cites the Russian opera Hovanštšina as an example.) Many speakers pronounce all of them s, or distinguish only between s and š, because Finnish has no voiced sibilants.^[33]

The language may be identified by its distinctive lack of the letters b, c, f, q, w, x, z and å.

¹ -te is added to make the sentence formal (T-V distinction). Otherwise, without the added "-te", it is informal. It is also added when talking to more than one person. The transition from second-person singular to second-person plural (teitittely) is a politeness pattern, advised by many "good manners guides". Elderly people, especially, expect it from strangers, whereas the younger might feel it to be too formal to the point of coldness. However, a learner of the language should not be excessively concerned about it. Omitting it is (almost) never offensive, but one should keep in mind that on formal occasions this custom may make a good impression.

J. R. R. Tolkien, although better known as an author, had a keen interest in languages from a young age, and became a professional philologist. He described his first encounter with Finnish:

Aspects of Finnish were a strong influence on Quenya, one of the languages constructed by Tolkien. Within his fantasy writings set in the world of Middle-earth, Quenya is a highly-revered language.