The Turkish copula is one of the more distinct features of Turkish grammar. In Turkish, copulas are called ek-eylem or ek-fiil ('suffix-verb'). Turkish is a highly agglutinative language and copulas are rendered as suffixes, albeit with a few exceptions.

Zero copula

Zero copula is the rule for third person, as in Hungarian and Russian. That means two nouns, or a noun and an adjective can be juxtaposed to make a sentence without using any copula. Third-person plural might be indicated with the use of plural suffix -lar/-ler.

To be (olmak versus imek)

Turkish "to be" as regular/auxiliary verb (olmak) and "to be" as copula (imek) contrasts. The auxiliary verb imek (i- is the root) shows its existence only through suffixes to predicates that can be nouns, adjectives or arguably conjugated verb stems, arguably being the only irregular verb in Turkish. The missing forms of i- are supplied by ol-: the infinitive olmak is an example, since there is no infinitive *imek. An infinitive ermek appeared in ancient texts; its stem er- became the current i-. The word idir, a variation of imek indicates alethic modality, so is used for emphasis, or to prevent ambiguity. İdir is an enclitic word, and exhibits vowel harmony when used as a suffix. Therefore Ali asker idir turns into Ali askerdir. In examples, emphasised word is written bold:

Negative copula

Negation is indicated by the negative copula değil. Değil is never used as a suffix, but it takes suffixes according to context.

Personal copulas

A complete sentence is formed by the addition of a suffix to a noun or adjective as an instance of nonverbal person agreement, with the conjugate verb "imek" only implied. These suffixes are, in origin, personal pronouns and indicate grammatical person. Öğretmen-i-m teacher-COP-1SG I am a/the teacher Öğretmen-si-n teacher-COP-2SG You are a/the teacher Öğretmen teacher He/she/it is a/the teacher Öğretmen-i-z teacher-COP-1PL We are (the) teachers Öğretmen-si-niz teacher-COP-2PL You [plural/formal] are (a/the) teacher(s) Öğretmen-ler teacher-PL They are (the) teachers

Past copulas

Alethic past tense is indicated with idi, another variation of imek. It is enclitic and exhibits vowel harmony like idir.

<section begin="list-of-glossing-abbreviations"/> ALETHIC:alethic <section end="list-of-glossing-abbreviations"/> Öğretmen-di-m teacher-ALETHIC-1SG I was a/the teacher (as I know) Öğretmen-di-n teacher-ALETHIC-2SG You were a/the teacher (as I know) Öğretmen-di teacher-ALETHIC He/she/it was a/the teacher (as I know) Öğretmen-di-k teacher-ALETHIC-1PL We were (the) teachers (as I know) Öğretmen-di-niz teacher-ALETHIC-2PL You [plural/formal] were (a/the) teacher(s) (as I know) Öğretmen-di-ler teacher-ALETHIC-PL They were (the) teachers (as I know) The [inferential](https://bliptext.com/articles/inferential-mood) past tense is indicated with imiş. It is enclitic and exhibits vowel harmony like idir. Öğretmen-miş-i-m teacher-INFER-COP-1SG I was a/the teacher (as I've heard) Öğretmen-miş-si-n teacher-INFER-COP-2SG You were a/the teacher (as I've heard) Öğretmen-miş teacher-INFER He/she/it was a/the teacher (as I've heard) Öğretmen-miş-i-z teacher-INFER-COP-1PL We were (the) teachers (as I've heard) Öğretmen-miş-si-niz teacher-INFER-COP-2PL You [plural/formal] were (a/the) teacher(s) (as I've heard) Öğretmen-ler-miş teacher-PL-INFER They were (the) teachers (as I've heard)

Conditional copulas

Conditional (hypothetical) mood is indicated with ise. It is enclitic and exhibits vowel harmony like idir. Öğretmen-se-m teacher-COND-1SG If I am a/the teacher Öğretmen-se-n teacher-COND-2SG If you are a/the teacher Öğretmen-se teacher-COND If he/she/it is a/the teacher Öğretmen-se-k teacher-COND-1PL If we are (the) teachers Öğretmen-se-niz teacher-COND-2PL If you [plural/formal] are (a/the) teacher(s) Öğretmen-ler-se teacher-PL-COND If they are (the) teachers