Hello everyone, it is my first post on this site.I have a question.What is the difference between these two words?Even though I am native turkish, it is hard to understand and translate these words into English.

Hi hoşgeldin,

I´ll give you an example for Yaptıysa in a sentence:

If he has done it then it´s all good.

Yaptısa, her şey hoş

Yapsaydı,

Well if he had done it on time, we wouldn´t have been so late to submitt our project, wouldn´t we.

has and had seem to be the keywords here between the two. I can give you more sentences if you want to really let it sink in, and cement it.

Sağol

My translations implies:

that something hasn´t been done

whislt the other implies:

one is not quite certain yet if it has or hasn´t been done. Not sure 100% yet. It´s not definitine yet. Almost like an assumption, taking for granted it´s been done.

I thank for your comments.

Interesting question. I can´t think of another case where you can change the order of the suffixes. Accoring to this http://www.turkishlanguage.co.uk/conditional.htm di + se is Past Reality Conditional, se + di is Past Unreality Conditional.

English example Past Reality Conditional - If you parked there, you get a ticket. 

English example Past Unreality Conditional - If you had parked there, you would have gotten a ticket.

How would I say in Turkish:

se and sa are conditional suffix´s in Turkish?

You mean you can´t order of suffix´s for these two words: Yapsaydı and Yaptıysa?