-іт

• -ыт (-yt), -т (-t)

From Proto-Turkic *-t.

-іт • (-ıt)

1. Used to form causative verbs.

   Synonyms: -гіз (-gız), -із (-ız), -ір (-ır), -дір (-dır), -тір (-tır)

   ‎ренжі- (renjı-, “to be offended”) + ‎-іт (-ıt) → ‎ренжіт- (renjıt-, “to offend”)

• 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, unless the word isn't monosyllabic. 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”)