The Most Similar Languages to Tajik

Tajik is an Indo-European language primarily spoken in Tajikistan. However, it has deep linguistic and cultural ties to several other languages spoken in Iran. According to the eLinguistics.net analysis using specific software modules to assess linguistic relationships, the five languages most similar to Tajik are Persian, Balochi, Mazandarani, Kurdish, and Zazaki.

1. Persian (90.4)
   Tajik is often considered a dialect of Persian. Historically, Persian was the language of literature, administration, and education across much of Central Asia. Due to their shared history, they share a common grammatical structure and vocabulary. However, they are written in different scripts: Persian uses the Arabic script, whereas Tajik is written in the Cyrillic script due to Soviet influence.
2. Balochi (77.8)
   Balochi, spoken by the Baloch people in Iran, Pakistan, and Afghanistan, is another close relative of Tajik. It belongs to the Western Iranian language group, sharing significant grammatical and lexical similarities with Tajik. Balochi has preserved many archaic features that have evolved in modern Persian. As a result, there are many Persian loanwords in Balochi.
3. Mazandarani (76.3)
   Mazandarani is primarily spoken along the southern coast of the Caspian Sea in Iran. This language is part of the Northwestern Iranian language group and shares a substantial amount of vocabulary and grammatical features with both Persian and Tajik. The proximity of the Mazandarani and Tajik people to Persian speakers has led to significant linguistic borrowing between them.
4. Kurdish (66.2)
   Spoken by the Kurdish people across several countries including Iran, Iraq, Syria, and Turkey, Kurdish is another language that is similar to Tajik. Kurdish belongs to the Northwestern Iranian languages. Kurdish shares many grammatical structures and vocabulary with Tajik, making it easier for speakers of one language to learn the other.
5. Zazaki (64.2)
   Zazaki is spoken in eastern Turkey and is part of the Northwestern Iranian languages. Zazaki exhibits significant similarities with Kurdish, particularly in its vocabulary and grammar. The language has several dialects. Both Zazaki and Tajik have significant linguistic influences from both Persian and Turkic languages.

(to be considered for the list, the language must be spoken by at least one million people)