The origin of the name Tolish is not clear but is likely to be quite old. The name of the people appears in early Arabic sources as Al-Taylasân and in Persian as Tâlišân and Tavâliš, which are plural forms of Tâliš. Northern Talysh (in the Republic of Azerbaijan) was historically known as Tâlish-i Guštâsbi. Talysh has always been mentioned with Gilan or Muqan. Hamdallah Mostowfi writing in the 1340s calls the language of Gushtaspi covering the Caspian border region between Gilan to Shirvan is called a Pahlavi language connected to the language of Gilan. Although there are no confirmed records, the language called in Iranian linguistics as Azari can be the antecedent of both Talyshi and Tati. Miller’s (1953) hypothesis that the Âzari of Ardabil, as appears in the quatrains of Shaikh Safi, was a form of Talyshi. That was also confirmed by Henning (1954). In western literature the people and the language are sometimes referred to as Talishi, Taleshi or Tolashi. Generally speaking, written documents about Taleshi are rare.
In the north of Iran, there are six cities where Talyshi is spoken: Masal, Rezvanshar, Talesh, Fouman, Shaft, and Masoleh (in these cities some people speak Gilaki and Turkish as well). The only towns where Talyshi is spoken exclusively are the townships of Masal and Masouleh. In other cities, in addition to Talyshi, people speak Gilaki and Azerbaijani. In Azerbaijan there are eight cities were Talysh is spoken: Astara (96%), Lerik (90%), Lenkoran (82%), Masalli (36%).[clarification needed]
Talyshi has been under the influence of Gilaki, Azeri Turkic, and Persian. In the south (Taleshdula, Masal, Shanderman, and Fumanat) Talyshis and Gilaks live side by side; however, there are less evidence that a Talyshi family replaces Gilaki with its own language. In this region the relation is more of a contribution to each other's language. In the north of Gilan, on the other hand, Azeri Turkic has replaced Talyshi in cities like Astara after the migration of Turkic speakers to the region decades ago. However, the people around Lavandvil and its mountainous regions has retained Talyshi. Behzad Behzadi, the author of "Azerbaijani Persian Dictionary" remarks that: "The inhabitants of Astara are Talyshis and in fifty years ago (about 1953) that I remember the elders of our family spoke in that language and the great majority of dwellers also conversed in Talyshi. In the surrounding villages, a few were familiar with Turkic". From around Lisar up to Hashtpar, Azeri and Talyshi live side by side, with the latter mostly spoken in small villages. To the south of Asalem, the influence of Azeri is negligible and the tendency is towards Persian along Talyshi[clarification needed] in cities. In the Azerbaijan republic, Talyshi is less under the influence of Azeri and Russian than Talyshi in Iran is affected by Persian. Central Talyshi has been considered the purest of all Talyshi dialects.
Talyshi belongs to the Northwestern Iranian branch of Indo-European languages. The living language most closely related to Talyshi is Tati. The Tati group of dialects is spoken across the Talysh range in the southwest[clarification needed] (Kajal and Shahrud) and south (Tarom). This Tatic family should not be confused with another Tat family which is more related to Persian. Talyshi also shares many features and structures with Zazaki, now spoken in Turkey, and the Caspian languages and Semnani of Iran.
The division of Talyshi into three clusters is based on lexical, phonological and grammatical factors. Northern Talyshi distinguishes itself from Central and Southern Talyshi not only geographically but culturally and linguistically as well. Speakers of Northern Talysh are found almost exclusively in the Republic of Azerbaijan but can also be found in the neighboring regions of Iran, in the Province of Gilan. The varieties of Talysh spoken in the Republic of Azerbaijan are best described as speech varieties rather than dialects. Four speech varieties are generally identified on the basis of phonetic and lexical differences. These are labeled according to the four major political districts in the Talysh region: Astara, Lankaran, Lerik, and Masally. The differences between the varieties are minimal at the phonetic  and lexical level. Mamedov (1971) suggests a more useful dialectal distinction is one between the varieties spoken in the mountains and those spoken in the plains. The morphosyntax of Northern Talysh is characterized by a complicated split system which is based on the Northwest Iranian type of accusativity/ergativity dichotomy: it shows accusative features with present-stem-based transitive constructions, whereas past-stem-based constructions tend towards an ergative behavior. In distant regions like Lavandevil and Masouleh, the dialects differ to such a degree that conversations begin to be difficult. In Iran, the northern dialect is in danger of extinction.
The major dialects of Talyshi
Northern (in Azerbaijan Republic and in Iran (Ardabil and Gilan provinces) from Anbaran to Lavandavil) including:
Central (in Iran (Gilan province) from Haviq to Taleshdula/Rezvanshahr district) Including:
Southern (in Iran from Khushabar to Fumanat) including:
The vowel system in Talyshi is more extended than in standard Persian. The prominent differences are the front vowel ü in central and northern dialects and the central vowel ə. In 1929, a Latin-based alphabet was created for Talyshi in the Soviet Union. However, in 1938 it was changed to Cyrillic-based, but it did not gain extensive usage for a variety of reasons, including political Stalinist consolidation of socialist nations. Nowadays, the Perso-Arabic script and Azeri Latin are used in Iran and Azerbaijan, respectively. The following tables contain the vowels and consonants used in Talyshi. The sounds of the letters on every row, pronounced in each language, may not correspond fully.
Talyshi has a subject–object–verb word order. In some situations the case marker, 'i' or 'e' attaches to the accusative noun phrase. There is no definite article, and the indefinite one is "i". The plural is marked by the suffixes "un", "ēn" and also "yēn" for nouns ending with vowels. In contrast to Persian, modifiers are preceded by nouns, for example: "maryami kitav" (Mary's book) and "kava daryâ" (livid sea). Like the most other Iranian dialects there are two categories of inflection, subject and object cases. The "present stem" is used for the imperfect and the "past stem" for the present in the verbal system. That differentiates Talyshi from most other Western Iranian dialects. In the present tense, verbal affixes cause a rearranging of the elements of conjugation in some dialects like Tâlešdulâbi, e.g. for expressing the negation of b-a-dašt-im (I sew), "ni" is used in the following form: ni-m-a-dašt (I don't sew)."m" is first person singular marker, "a" denotes duration and "dašt" is the past stem.
The past stem is inflected by removing the infinitive marker (ē), however the present stem and jussive mood are not so simple in many cases and are irregular. For some verbs, present and past stems are identical. The "be" imperative marker is not added situationally. The following tables show the conjugations for first-person singular of "sew" in some dialects of the three dialectical categories:
There are four "cases" in Talyshi, the nominative (unmarked), the genitive, the (definite) accusative and ergative. The accusative form is often used to express the simple indirect object in addition to the direct object. These "cases" are in origin actually just particles, similar to Persian prepositions like "râ".
^مستوفی، حمدالله: «نزهةالقلوب، به كوشش محمد دبیرسیاقی، انتشارات طهوری، ۱۳۳۶. Mostawafi, Hamdallah, 1336 AP / 1957 AD. Nozhat al-Qolub. Edit by Muhammad Dabir Sayyaqi. Tahuri publishers. (Persian)
^Henning, W. B. 1954. The Ancient Language of Azerbaijan. Transactions of the Philological Society, London. p 157-177. 
^ abcdAsatrian, G. and H. Borjian, 2005. Talish: people and language: The state of research. Iran and the Caucasus 9/1, p 43-72
^Behzadi, B, 1382 AP / 2003 AD. Farhange Azarbâyjani-Fârsi (Torki), p. 10. Publication: Farhange Moâser. ISBN 964-5545-82-X
In Persian: حقیقت تاریخی این است که آذربایجانی، ایرانی است و به زبان ترکی تکلم میکند. اینکه چگونه این زبان در بین مردم رایج شد، بحثی است که فرصت دیگر میخواهد. شاهد مثال زیر میتواند برای همه این گفتگوها پاسخ شایسته باشد. اهالی آستارا طالش هستند و تا پنجاه سال پیش که نگارنده به خاطر دارد پیران خانواده ما به این زبان تکلم میکردند و اکثریت عظیم اهالی نیز به زبان طالشی صحبت میکردند. در دهات اطراف شاید تعداد انگشتشماری ترکی بلد بودند.
^ abcdefgAbdoli, A. 1380 AP / 2001 AD. Farhange Tatbiqiye Tâleši-Tâti-Âzari (Comparative dictionary of Talyshi-Tati-Azari), p 31-35, Publication:Tehran, "šerkate Sahâmiye Entešâr" (Persian).
^Stilo, D. 1981. The Tati Group in the Sociolinguistic Context of Northwestern Iran. Iranian Studies XIV
Asatrian, G., and Habib Borjian, 2005. Talish: people and language: The state of research. Iran and the Caucasus 9/1, pp. 43–72 (published by Brill).
Bazin, M., 1974. Le Tâlech et les tâlechi: Ethnic et region dans le nord-ouest de l’Iran, Bulletin de l’Association de Geographes Français, no. 417-418, 161-170. (French)
Bazin, M., 1979. Recherche des papports entre diversité dialectale et geographie humaine: l’example du Tâleš, G. Schweizer, (ed.), Interdisciplinäre Iran-Forschung: Beiträge aus Kulturgeographie, Ethnologie, Soziologie und Neuerer Geschichte, Wiesbaden, 1-15. (French)
Bazin, M., 1981. Quelque échantillons des variations dialectales du tâleši, Studia Iranica 10, 111-124, 269-277. (French)