Merhaba, I am a complete beginner in Turkish language, so please forgive this question.

I know that to negate a verb one has to insert either MI; Mİ, MU or MÜ (according to voewl harmony).

Bilmiyorum, anlamıyorum; okumuyorum...

Do the very same particles apply for negating the past? or do we have also

bilmidim; anlamadım; okumudum

teşekkürler!!

Good question. For past tense, it´s ma/me:

Anlamadım is correct.

To negate verbs you generally use the me/ma suffix.

The present continuous tense is slightly different in that the negation is shortened to just the ´m´ part, and then the ´iyor´ suffix is added depending on vowel harmony with the last letter of the verb stem.

First person (I) examples -

bilmedim, anlamadım, okumadım (negative past)

bilmeyeceğim, anlamayacağım, okumayacağım (negative future)

Bilmem, anlamam, okumam (negative aorist)

* The suffix to negate a verb is -ME/MA. 

* The present continuous tense suffix is -yor

* With present continuous tense -e/a ---> ı-i-u-ü alteration happens. 

gel + me + yor ----> gel + mi + yor [he/she is not coming]

kal + ma+ yor ----> kal + mı + yor [he/she is not staying]

oku + ma + yor ----> oku + mu + yor [ he/she is not reading]

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*Negating simple past tense verbs,  there is no vowel alteration with -ma/me

gelmedi

kalmadı

okumadım