A thorough presentation of the Tatar language characteristic is hindered by the fact that there are no writing materials in the ethnic language of the Lithuanian Tatars (Łapicz 1986: 39Łapicz 1986 / komentarz/comment/r /
Łapicz, Czesław 1986. Kitab Tatarów litewsko-polskich (Paleografia. Grafia. Język). Toruń: UMK.
). A brief outline of this characteristic is possible through the comparison with the currently spoken Turkic languages and knowing their history, and also because of the presence of family names and religious terminology of Turkic-Tatar origin.

Genetic classification

The Tatar language belonged to the Turkic language family (sometimes considered to be a subfamily of Altaic languages), a Kipchak group, Kipczak-Cuman subgroup. The currently spoken languages, of which names consist of the label ‘Tatar’, that is the Tatar language TAT and Crimean Tatar, belong to two different subgroups of the Kypchak languages: Kipczak-Bolgar and Kipczak-Cuman. This difference allows us to note the fact that the language of the Tatar settlers on the Polish land dates back to the time before this distinction.

Typological classification

All attempts for typological characteristic of the Tatar language needs to be preceded by a note that Kipchak and Bashkir dialects, from which the Tatar language originated, did not form a language system, which would be common to all tribal groups. The Tatar language was probably a SOV language. As well as other Turkic languages, it was an agglutinative language.
Most can be said about the language’s phonetics. The typological comparisons and the preserved data allow the claim that the language had 9 vowels. There are no data that would allow us to confirm whether there was a distinction between long and short vowels. In Tatar the Turkic initial voiced [ɣ] disappeared and  [ǰ] changed into  [j] (e.g. ǰafair : jawair,,’a family name’).

Influence of other languages on Tatar

Tatars very often serve as translators/interpreters in the Polish army in contacts with the Ottoman Empire. This is considered to be one of the reasons for many borrowings from Ottoman-Turkic language, which created the second Turkic layer in Tatar, after the Old Uyghur. Borrowings were predominantly in the vocabulary related to religion sphere. Those word came into the Ottoman-Turkic language as borrowings from Arabic or Persian. Arabic was not a direct source of borrowings to Tatar, as the words discussed here have the forms which are very close to the Ottoman-Turkic language.
The example of the Ottoman-Turkish is the Tatar word namaztyk ‘a prayer rug’, in which we can recognise the Persian word namaz for ‘prayer’ and the Turkic suffix –tyk. The word biesz wacht namaz ‘five daily prayer timing’ is an example which shows words from three different languages in one word: Turkic, Arabic and Persian (in order).
Sometimes a word of Turkic origin came to Tatar through Polish. The name Tamerlan used by the Tatars has Turkic and Persian roots, but in Tatar it was a borrowing from Polish, which borrowed the word from Western European languages. The Polish Tatars still use double names - one of Turkic and one of Slavic origin.
Frequently, there are names which are phonetically close e.g. Mustafa – Stefan (Jankowski 1997: 67Jankowski 1997 / komentarz/comment/r /
Jankowski, Henryk 1997. "Nazwy osobowe Tatarów litewsko-polskich", Rocznik Tatarów Polskich. Tom IV. Gdańsk: Związek Tatarów Polskich, s. 59-90.
).
Contact with the Slavic languages caused many changes in Tatar language. The influence of Belarusian and Polish can be seen in phonetics, as well as in morphology and lexicon.
The influence of Belarusian on the Tatar is visible in e.g. consonant palatalisation, when it is surrounded by frontal consonants in the words of the Eastern origin, e.g. in the word ewwiel ‘before/in front of’ (Turkic: evvel , Arabic. awwal) or in the word mieczeć ‘mosque’.
The words ending in -i gained endings -ej e.g.mufti > muftej ‘the highest minister’. There are also Slavic adjective endings, such as ny(j) (e.g. chalalnyj ‘allowed), -ski (np. related to Mekka’) czy –owy(j) (e.g. ramazanowy ‘related to Ramadan’). Above all, Slavic word-formation suffixes, such as -czyk (e.g. alejczyk ‘Shi'ite, Ali's supporter).
In the lexicon there are e.g. verbs derived from Tatar words by adding Slavic verbal suffix (e.g. azanić ‘to call for prayer’). The characteristic and interesting feature of Tatar is the presence of compound verbs, the verb of which is of the Slavic origin, and the noun, as an instance, of the Turkic origin, e.g.  terbie czynić ‘repent’ (Turkic: óvbe metek) or abdes uziąć ‘perform one’s ablutions’ (Turkic: aptes almak).
The influence of Christian vocabulary can be seen especially in the Tatar Kitabs, e.g. by the presence of Polish lucyper ‘Polish Lucifer’ or  ‘chóry anielskie’ angelic choirs. In the Kitab texts, which explain Koran, the Polish nobility sociolect appears (e.g. Prorok Jego Milosc ‘ Prophet His Grace’, and in Islamic parables, we can see the Polonised elements of the presented world: dwór, pułk, wojewoda ('manor, regiment, province governor').
Single Tatar words indicate the influence of grammatical gender present in the Slavic languages - an unknown class for the Turkic languages, e.g. zehid ‘ascetic-male’ > zehidka ‘ascetic-female’.
In some Tatar words there are also Slavic plural endings, e.g. huruf : hurufy ‘letters’, szehid: szehidowie ’martyrs for faith’. In case of plural, sometimes there was a duplication of exponents of grammatical class of identical meaning, e.g. Turkic du’ālar > Polish-Tatar dualary ‘prayers’.

Influence of Tatar on other languages

The borrowings from Tatar can be mostly found in the East Slavic languages (Stachowski 2007: VIIStachowski 2007 / komentarz/comment/r /
Stachowski, Stanisław 2007. Słownik historyczny turcyzmów w języku polskim. Kraków: Księgarnia Akademicka.
).
The Turkic gerund suffix –(V)š, for example, is of Tatar origin. It is present in the East Slavic languages as a different suffix, but it is not to be found in other Slavic languages. In can be seen in the old Slavic names, e.g. Jarosz ( > Jaroslaw) (Jankowski 1997: 84Jankowski 1997 / komentarz/comment/r /
Jankowski, Henryk 1997. "Nazwy osobowe Tatarów litewsko-polskich", Rocznik Tatarów Polskich. Tom IV. Gdańsk: Związek Tatarów Polskich, s. 59-90.
).
The Tatar influence on the Polish language can be predominantly seen in lexicon, although there are only few direct borrowings from Tatar. The word ulan ‘uhlan’ comes from Tatar, and in Tatar it means ‘boy, gallant’. In the variation of the Polish language used currently by the Polish Tatars, we can encounter the name bielusz - meaning ‘dumpling with meat’. It comes from the Kipchak verb biele ’wrap up in nappy’. Also a word for the Islam minister molna is a good example of consonant dissimilation, which is a typical Kipchak feature.
Dissimilation occured when the word mullah was pronunced mołła in Polish [mɔɫɫa].