Tajik language is the literary and national language of Tajiks and the state language of the Republic of Tajikistan. The Tajik language is also studied by the Tajiks of the republics of Uzbekistan, Kyrgyzstan, Kazakhstan, as well as in the Tajik-inhabited regions of Afghanistan. The Persian language of the Somonians was called «Persian, Persian» or «Persian Dari», and despite the fact that this language was sometimes called «Tajik language» or «Tajik zufon» in the written works of the Middle Ages (in a Port Monavian text, which was found in Turfan, China (8th century), the term tazigāne āvak «Tajik language» was used), but while the Tajik people [1] were not called «Persians», their language as a whole until the 19th century and the beginning of the 20th century the name «Persian» was represented. The environment of the formation of the new Persian language, the historical relations of the owners of this language with neighboring peoples could not be without influence on the historical evolution of the vocabulary of this language. The combination of the Persian language with the Portuguese language led to the introduction of Portuguese derived words into its vocabulary. The existence of a number of East Iranian quotations (especially Sogdian words such as nagz, zasal, magz, bot, alagda, etc.) in the lexical structure of the Persian language is also a result of the historical connection between these languages.

Thus, over several centuries, the vocabulary of the Persian language was formed and perfected, and until the 16th century, this language was considered the common literary language in the east and west of historical Iran. After the bloody conflicts between the Safavids and the Shaibanis, which started on religious grounds, all connections between the inhabitants of Upper Nahr and Khorasan and the western part of Iran were cut off, and this political-religious demarcation led to a cultural and literary separation.

From the 16th century onwards, language and literature developed independently and separately in two Persian-speaking lands — Movarunnahr and the Persian state, which, despite the commonality of literary norms, led to the emergence of differences in the vocabulary, grammar and style of speech and writing of the Persian-speaking people. these two lands became. For example, in the book «Majma-ut-tavarih» (16th century), which belongs to the authors of Central Asia, many grammatical features are reflected, which are characteristic of today’s Tajik dialects. Among these features are the use of certain (continuous) forms of the verb with the auxiliary verb to stand (he is shaving, he was fighting, etc.), present tense verbs with the components of staying (he stayed), leaving (he took away), coming (ran away). came), took (cut), saw (read saw), went to work in the present participle of the 2nd person plural -eton (bury kuneton) and special features of the use of prefixes and suffixes can be mentioned. In the works of Ahmed Donish and other writers of the 19th century, the characteristics of Tajik dialects are more visible, which are different from the literary language common in Iran of the same period.

Thus, the Tajik literary language gradually acquired new characteristics based on local Tajik dialects, and this process took place at the end of the 11th century and the beginning of the 20th century, especially in the works of educational writers of that time, such as Sadriddin Aini, Abdurrauf Fitrat, Sadri Ziya, Mirzo Siroji Hakim, Toshhoja Asiri and others became clearly visible..