Serbian (српски / srpski , pronounced [sr̩̂pskiː] ) is the standardized variety of the Serbo-Croatian language mainly used by Serbs.  It is the official language of Serbia, the territory of Kosovo, and one of the three official languages of Bosnia and Herzegovina. In addition, it is a recognized minority language in Montenegro where it is spoken by the relative majority of the population,  as well as in Croatia, Macedonia, Romania, Hungary, Slovakia, and the Czech Republic.
Standard Serbian is based on the most widespread dialect of Serbo-Croatian, Shtokavian (more specifically on Šumadija-Vojvodina and Eastern Herzegovinian dialects  ), which is also the basis of Standard Croatian, Bosnian, and Montenegrin.  The other dialect spoken by Serbs is Torlakian in southeastern Serbia, which is transitional to Macedonian and Bulgarian.
Serbian is practically the only European standard language whose speakers are fully functionally digraphic,  using both Cyrillic and Latin alphabets. The Serbian Cyrillic alphabet was devised in 1814 by Serbian linguist Vuk Karadžić, who created the alphabet on phonemic principles. The Latin alphabet was designed by Croatian linguist Ljudevit Gaj in 1830.
Serbian is a standardized variety of Serbo-Croatian,  a Slavic language ( Indo-European), of the South Slavic subgroup. Other standardized forms of Serbo-Croatian are Bosnian, Croatian, and Montenegrin. It has lower intelligibility with the Eastern South Slavic languages Bulgarian and Macedonian, than with Slovene (Slovene is part of the Western South Slavic subgroup, but there are still significant differences in vocabulary, grammar and pronunciation to the standardized forms of Serbo-Croatian, although it is closer to the Kajkavian and Chakavian dialects of Serbo-Croatian).
Figures of speakers according to countries:
- Serbia: 6,540,699 (official language)
- Bosnia and Herzegovina: 1,086,027  (co-official language)
- Germany: 568,240
- Austria: 350,000
- Montenegro: 265,890 (recognized minority language)
- Switzerland: 186,000
- United States: 172,874
- Sweden: 120,000
- Italy: 106,498 
- Canada: 72,690 
- Australia: 55,114  
- Croatia: 52,879  (recognized minority language)
- Slovenia: 38,964
- Republic of Macedonia: 35,939 (recognized minority language)
- Romania: 22,518 (recognized minority language)
Status in Montenegro
Serbian was the official language of Montenegro until 2007 when the new Constitution of Montenegro replaced the Constitution of 1992. Amid opposition from pro-Serbian parties,  the Montenegrin language was made the sole official language of the country, and Serbian was given the status of a recognised minority language along with Bosnian, Albanian, and Croatian. 
According to the 2011 Montenegrin census, 42.88% declare Serbian to be their native language, while Montenegrin is declared by 36.97% of the population.
Differences between standard Serbian and standard Croatian and Bosnian
Although Serbian language authorities have recognized the official status of both scripts in contemporary Standard Serbian for more than half of a century now, due to historical reasons, the Cyrillic script was made the official script of Serbia's administration by the 2006 Constitution.  However, the law does not regulate scripts in standard language, or standard language itself by any means, leaving the choice of script as a matter of personal preference and to the free will in all aspects of life (publishing, media, trade and commerce, etc.), except in government paperwork production and in official written communication with state officials, which have to be in Cyrillic. Even in official government documents this constitutional requirement is rarely enforced. Serbian is a rare example of synchronic digraphia, a situation where all literate members of a society have two interchangeable writing systems available to them. Media and publishers typically select one alphabet or another. For example, the public broadcaster, Radio Television of Serbia, predominantly uses the Cyrillic script whereas the privately run broadcasters, like RTV Pink, predominantly use the Latin script.
A survey from 2014 showed that 47% of the Serbian population favors the Latin alphabet whereas 36% favors the Cyrillic one. 
The sort order of the ćirilica (ћирилица) alphabet:
- Cyrillic order called Azbuka (азбука): А Б В Г Д Ђ Е Ж З И Ј К Л Љ М Н Њ О П Р С Т Ћ У Ф Х Ц Ч Џ Ш
The sort order of the latinica (латиница) alphabet:
- Latin order called Abeceda (абецеда): A B C Č Ć D Dž Đ E F G H I J K L Lj M N Nj O P R S Š T U V Z Ž
Serbian verbs are conjugated in four past forms— perfect, aorist, imperfect, and pluperfect —of which the last two have a very limited use (imperfect is still used in some dialects, but the majority of native Serbian speakers consider it archaic), one future tense (also known as the first future tense, as opposed to the second future tense or the future exact, which is considered a tense of the conditional mood by some contemporary linguists), and one present tense. These are the tenses of the indicative mood. Apart from the indicative mood, there is also the imperative mood. The conditional mood has two more tenses: the first conditional (commonly used in conditional clauses, both for possible and impossible conditional clauses) and the second conditional (without use in the spoken language—it should be used for impossible conditional clauses). Serbian has active and passive voice.
Most Serbian words are of native Slavic lexical stock, tracing back to the Proto-Slavic language. There are many loanwords from different languages, reflecting cultural interaction throughout history. Notable loanwords were borrowed from Greek, Latin, Italian, Turkish, Hungarian, Russian, and German.
Serbian literature emerged in the Middle Ages, and included such works as Miroslavljevo jevanđelje ( Miroslav's Gospel) in 1192 and Dušanov zakonik ( Dušan's Code) in 1349. Little secular medieval literature has been preserved, but what there is shows that it was in accord with its time; for example, Serbian Alexandride , a book about Alexander the Great, and a translation of Tristan and Iseult into Serbian. Although not belonging to the literature proper, the corpus of Serbian literacy in the 14th and 15th centuries contains numerous legal, commercial and administrative texts with marked presence of Serbian vernacular juxtaposed on the matrix of Serbian Church Slavonic.
In the mid-15th century, Serbia was conquered by the Ottoman Empire and for the next 400 years there was no opportunity for the creation of secular written literature. However, some of the greatest literary works in Serbian come from this time, in the form of oral literature, the most notable form being Serbian epic poetry. The epic poems were mainly written down in the 19th century, and preserved in oral tradition up to the 1950s, a few centuries or even a millennium longer than by most other "epic folks". Goethe and Jacob Grimm learned Serbian in order to read Serbian epic poetry in the original. By the end of the 18th century, the written literature had become estranged from the spoken language. In the second half of the 18th century, the new language appeared, called Slavonic-Serbian. This artificial idiom superseded the works of poets and historians like Gavrilo Stefanović Venclović, who wrote in essentially modern Serbian in the 1720s. These vernacular compositions have remained cloistered from the general public and received due attention only with the advent of modern literary historians and writers like Milorad Pavić. In the early 19th century, Vuk Stefanović Karadžić promoted the spoken language of the people as a literary norm.
- Rečnik srpskohrvatskog književnog i narodnog jezika (Dictionary of Serbo-Croatian standard language and vernaculars) is the biggest dictionary of Serbian and still unfinished. Starting with 1959, 16 volumes were published, about 40 are expected. Works of Croatian authors are excerpted, if published before 1991.
- Rečnik srpskohrvatskoga književnog jezika in 6 volumes, started as a common project of Matica srpska and Matica hrvatska, but only the first three volumes were also published in Croato-Serbian (hrvatskosrpski).
- Rečnik srpskoga jezika ( ISBN 978-86-7946-004-2) in one volume, published in 2007 by Matica srpska, which on more than 1500 pages in A4 format explains more than 85.000 entries. Several volume dictionaries were published in Croatia (for the Croatian language) since the 1990s ( Anić , Enciklopedijski rječnik , Hrvatski rječnik ).
- Standard dictionaries
- Specialized dictionaries
- Phraseological dictionaries
Vuk Karadžić's Srpski rječnik , first published in 1818, is the earliest dictionary of modern literary Serbian. The Rječnik hrvatskoga ili srpskoga jezika (I–XXIII), published by the Yugoslav Academy of Sciences and Arts from 1880 to 1976, is the only general historical dictionary of Serbo-Croatian. Its first editor was Đuro Daničić, followed by Pero Budmani and the famous Vukovian Tomislav Maretić. The sources of this dictionary are, especially in the first volumes, mainly Štokavian. There are older, pre-standard dictionaries, such as the 1791 German–Serbian dictionary.
The standard and the only completed etymological dictionary of Serbian is the "Skok", written by the Croatian linguist Petar Skok: Etimologijski rječnik hrvatskoga ili srpskoga jezika ("Etymological Dictionary of Croatian or Serbian"). I-IV. Zagreb 1971–1974.
There is also a new monumental Etimološki rečnik srpskog jezika (Etymological Dictionary of Serbian). So far, two volumes have been published: I (with words on A-), and II (Ba-Bd).
There are specialized etymological dictionaries for German, Italian, Croatian, Turkish, Greek, Hungarian, Russian, English and other loanwords (cf. chapter word origin ).
- Kosovsko-resavski dialect dictionaries:
- Gliša Elezović, Rečnik kosovsko-metohiskog dijalekta I-II. 1932/1935.
- Prizren-Timok (Torlakian) dialect dictionaries:
- Brana Mitrović, Rečnik leskovačkog govora. Leskovac 1984.
- Nikola Živković, Rečnik pirotskog govora. Pirot, 1987.
- Miodrag Marković, Rečnik crnorečkog govora I-II. 1986/1993.
- Jakša Dinić, Rečnik timočkog govora I-III.1988–1992.
- Jakša Dinić, Timocki dijalekatski recnik, (Institut za srpski jezik, Monografije 4; ISBN 978-86-82873-17-4) Beograd 2008,
- Momčilo Zlatanović, Rečnik govora južne Srbije. Vranje, 1998, 1–491.
- East-Herzegovinian dialect dictionaries:
- Milija Stanić, Uskočki rečnik I–II. Beograd 1990/1991.
- Miloš Vujičić, Rečnik govora Prošćenja kod Mojkovca. Podgorica, 1995.
- Srđan Musić, Romanizmi u severozapadnoj Boki Kotorskoj. 1972.
- Svetozar Gagović, Iz leksike Pive. Beograd 2004.
- Zeta-Pešter dialect:
- Rada Stijović, Iz leksike Vasojevića. 1990.
- Drago Ćupić – Željko Ćupić, Rečnik govora Zagarača. 1997.
- Vesna Lipovac-Radulović, Romanizmi u Crnoj Gori – jugoistočni dio Boke Kotorske. Cetinje – Titograd, 1981.
- Vesna Lipovac-Radulović, Romanizmi u Budvi i Paštrovićima. Novi Sad 1997.
- Rečnik sprskih govora Vojvodine. Novi Sad.
- Mile Tomić, Rečnik radimskog govora – dijaspora, Rumunija. 1989.