-тір

• -тыр (-tyr)

From Proto-Turkic *-tur.

-тір • (-tır)

1. Used to form causative verbs.

   Synonyms: -іт (-ıt), -гіз (-gız), -із (-ız), -ір (-ır), -дір (-dır)

   ‎өл- (öl-, “to die”) + ‎-тір (-tır) → ‎өлтір- (öltır-, “to kill”)

• All the causative suffixes are synonymous and carry the same meaning, but the usage is irregular and you can't know which one should be used. The only rule is that -т (-t) is always used after a vowel. Sometimes some verbs may have a few synonymous causatives formed by different suffixes:

  жаз- (jaz-, “to write”) + -ғыз (-ğyz) > жазғыз- (jazğyz-, “to make someone write”)

  жаз- (jaz-, “to write”) + -дыр (-dyr) > жаздыр- (jazdyr-, “to make someone write”)

• And it is also possible to attach multiple suffixes, either forming a new meaning or just keeping the same one:

  оқы- (oqy-, “to read”) + -т (-t) -қыз (-qyz) > оқытқыз- (oqytqyz-, “to make someone read”)

  өл- (öl-, “to die”) + -тір (-tır) > өлтір- (öltır-, “to kill”) + -т (-t) > өлтірт- (öltırt-, “to make someone kill”)