Turkish language belongs to the Altay branch of the Ural-Altaic linguistic family, same as Finnish and Hungarian languages. It is the westernmost of the Turkic languages spoken across Central Asia and is generally classified as a member of the South-West group, also known as the Oguz group. Other Turkic languages, all of which are closely related, include Azerbaijani (Azeri), Kazakh, Kyrgyz, Tatar, Turkmen, Uighur, Uzbek, and many others spoken from the Balkans across Central Asia into northwestern China and southern Siberia. Turkic languages are often grouped with Mongolian and Tungusic languages in the Altaic language family. Strictly speaking, the "Turkish" languages spoken between Mongolia and Turkey should be called Turkic languages, and the term "Turkish" should refer to the language spoken in Turkey alone. It is common practice, however, to refer to all these languages as Turkish, and differentiate them with reference to the geographical area, for example, the Turkish language of Azerbaijan.
Through the span of history, Turks have spread over a wide geographical area, taking their language with them. Turkish speaking people have lived in a wide area stretching from today's Mongolia to the north coast of the Black Sea, the Balkans, East Europe, Anatolia, Iraq and a wide area of northern Africa. Due to the distances involved, various dialects and accents have emerged. Turkish is also the language spoken at home by people who live in the areas that were governed by the Ottoman Empire. For instance, in Bulgaria there are over a million speakers. About 50,000 Turkish speakers live in Uzbekistan, Kazakhstan, Kyrgyzstan, Tajikistan, and Azerbaijan. In Cyprus, Turkish is a co-official language (with Greek) where it is spoken as a first language by 19 percent of the population, especially in the North (KKTC). Over 1.5 million speakers are found in Bulgaria, Macedonia, and Greece; over 3 million speakers live in Germany (and other northern European countries) where Turks have for many years been "guest workers." About 40,000 Turkish speakers live in the United States.
Turkish has several dialects. The Turkish dialects can be divided into two major groups: Western dialects and Eastern dialects. Of the major Turkish dialects, Danubian appears to be the only member of the Western group. The following dialects make up the Eastern group: Eskisehir, Razgrad, Dinler, Rumelian, Karamanli, Edirne, Gaziantep, and Sanliurfa. There are some other classifications that distinguish the following dialect groups: South-western, Central Anatolian, Eastern, Rumelian, and Kastamonu dialects. Modern standard Turkish is based on the Istanbul dialect of Anatolia.
The history of the language is divided into three main groups, old Turkish (from the 7th to the 13th centuries), mid-Turkish (from the 13th to the 20th) and new Turkish from the 20th century onwards. During the Ottoman Empire period Arabic and Persian words invaded the Turkish language and it consequently became mixed with three different languages. During the Ottoman period which spanned six centuries, the natural development of Turkish was severely hampered. Turkish formed the basis for Ottoman Turkish, the written language of the Ottoman Empire. Ottoman Turkish was basically Turkish in structure, but with a heavy overlay of Arabic and Persian vocabulary and an occasional grammatical influence. Ottoman Turkish co-existed with spoken Turkish, with the latter being considered a "gutter language" and not worthy of study. Ottoman Turkish, and the spoken language were both represented with an Arabic script.
Then there was the "new language" movement started by Kemal Atatürk. In 1928, five years after the proclamation of the Republic, the Arabic alphabet was replaced by the Latin one, which in turn speeded up the movement to rid the language of foreign words. Prior to the reform that introduced the Roman script, Turkish was written in the Arabic script. Up to the 15th century the Anatolian Turks used the Uighur script to write Turkish. The Turkish Language Institute (Türk Dil Kurumu) was established in 1932 to carry out linguistic research and contribute to the natural development of the language. As a consequence of these efforts, modern Turkish is a literary and cultural language developing naturally and free of foreign influences. Today literacy rates in Turkey are over 96%.
Like all of the Turkic languages, Turkish is agglutinative, that is, grammatical functions are indicated by adding various suffixes to stems. Separate suffixes on nouns indicate both gender and number, but there is no grammatical gender. Nouns are declined in three declensions with six case endings: nominative, genitive, dative, accusative, locative, and ablative; number is marked by a plural suffix. Verbs agree with their subjects in case and number, and, as in nouns, separate identifiable suffixes perform these functions. The order of elements in a verb form is: verb stem + tense aspect marker + subject affix. There is no definite article; the number "one" may be used as an indefinite article.
Subject-Object-Verb word order in Turkish is a typical Turkic characteristic, but other orders are possible under certain discourse situations. As a SOV language where objects precede the verb, Turkish has postpositions rather than prepositions, and relative clauses that precede the verb.
Turkish has 8 vowels, and 21 consonants. It also has Turkic vowel harmony in which the vowels of suffixes must harmonize with the vowels of noun and verb stems; thus, for example, if the stem has a round vowel then the vowel of the suffix must be round, and so on. Stress on words pronounced in isolation is on the final syllable, but in discourse, stress assignment is complicated especially in the verb.