i didn´t understand :word Mutation & suffix mutation .

can someone help me

I´m not sure where to start. Have you read the lessons on the subject?

Consonant harmony

Consonant mutation

Consonant changes

As a learner I understand the rules like this.

Consonant mutation: When certain Turkish words* end with the following letters p, ç, t, and k, the letters change when you add a suffix starting with a vowel. (*often single syllable words are exceptions to this rule)

eg (p changing to b) kitap (book) kitabım (my book, kitap + ım)

(ç changing to c) ağaç (tree) ağaca (to the tree, ağaç + a)

(k changing to ğ ) köpek (dog) köpeğim (my dog, köpek + im)

(t changing to d) öğüt (advice) öğüdüm (my advice, öğüt + üm)

(words ending in nk changing to a g) renk (colour) rengimiz (our colour)

Suffix consonant mutation: When suffixes starting with c or d follow words ending with p ç f h k s ş or t  then the first letter of the suffix changes (mutates)

For example:

(suffix starting with c changing to ç )

Türk + ce = Türkçe  (Turkish language)

(suffix starting with d changing to t )

otobüs (bus) + den (from) = otobüsten (from the bus)

yap (do) + dım (past tense for ´I´ ) = yaptım (I did)

I hope this helps you. 

thx ... but  what does mean the suffix ce ?

Read this previous post

in particular number 9

i don´t worry about this kind of stuff, the nitty gritties of grammar - just learn the lingo the way kids do, the generalizations will crystalize out naturally the more simple words and frases you learn. The eggheads have actually measured it and found out that your are better off knowing more words and simple expressions than having perfect grammar, that´s for getting around on the daily basis. ... Hoşça kal !  ^_^