translate yasemin bir kaç kez garip sorular sordu da cevap vermedim

my try

Yasemin a few times asked strange questions also, (but) I didn´t give an answer.

nice one Henry. also is wrong to put there. you could say ´also´ only if sentence was like "sorular da sordu" which means "Yasemin asked strange questions too among other stuff."

Bunu anlamadım. "Why is Yasemin a few times asked strange questions also, I didn´t give an answer." not correct and what should it be?

"sorular sordu da cevap vermedim."

although you should have put ama there instead of da, it still means "but" in that sentence, not ´also´

Difference:

Sorular sordu da cevap vermedim: She asked questions but I didnt answer.

Sorular da sordu, cevap vermedim: She also asked questions, I didnt answer.