The Past Simple Tense, also known as the Definite Past or -di Past (Belirli Geçmiş Zaman), is used for actions completed in the past that were witnessed or are known for certain by the speaker.

Suffix Formation:

The suffix is -dı / -di / -du / -dü following I-Type vowel harmony, or -tı / -ti / -tu / -tü if the verb stem ends in a voiceless consonant (f, s, t, k, ç, ş, h, p - "FıSTıKÇı ŞaHaP") due to consonant assimilation.

• gel- → geldi (came)
• yap- (ends in 'p') → yaptı (did)
• oku- → okudu (read)
• gör- → gördü (saw)

Conjugation (yapmak - to do):

Negation:

The negative is formed by adding the negative suffix -me/-ma to the verb stem before the past tense suffix: -medi/-madı. Example: Ben yapmadım. (I didn't do.)