Hi, I have an exercise to fill the gaps with "-a/-e" or "-ıp/-ip".

For example:

Ahmet gel... git... sorular soruyor.

Geçen yılki soğuklarda düş... kalk... işyerine kadar gittim.

Can someone expain this to me? 

Thanks!

Gelip gidip, düşe kalka

I am sure other members who are more intererested in Turkish grammar will give you a long explanation. Here is my explanation :

These are adverbs. They are telling us how the action happens. 

When you ask the verb how, the answer will be these adverbs.

ex: soruyor means "he/she is asking". Lets ask how is he/she asking? Answer: gelip gidip. That means "by coming and going" . It means he/ she comes and then goes often to ask the question.

düşe kalka means "by falling down and standing up". This means "with a lot of difficulty" in Turkish. 

If you want to be able to put the correct suffixes you should learn how to use these adverbs by reading about them.

Ahmet gelip gidip sorular soruyor.

gelmek gitmek

Ahmet geliyor ve gidiyor ve sorular soruyor.

geliyor ve gidiyor

gelİYOR VE gidİYOR

gelip gidiyor

gelip gidİYOR ve sorular sorUYOR

gelip gidip sorular soruyor.

Ahmet gelip gidiyor ve sorular soruyor. (this is good alternative, too)

Ahmet gelip gidip sorular soruyor. (this is better than it.)

http://www.turkishclass.com/turkish_lesson_326 (-ip)

http://www.turkishclass.com/turkish_lesson_363 (-e)

to express the way the event happened. This clause requires two verbs. Both are conjugated in the same way.

by the way, the correct orthography is "iş yeri"