Iwant to know if rule in turkish

olsam,san,eğer,keşke

thanks.

Here are some links as it is not so simple to explain

Erdinc´s answer

Manisa Turkish conditionals 

Thanks

And here are some more links

si++´s answer

aslan2´s answer

And my basic understanding is that 

eğer (means if), and is used at the start of the sentence or phrase, for emphasis (note that it should still be used with the ´ise´ suffix attached to the verb. It also helps learners recognise a conditional sentence 

keşke .... means something like ´if only ...´, or can be used like ´I wish ...´

some examples

keşke benimle gelebilsen = I wish you could come with me, if only you could come with me

keşke burada olsaydın = I wish you were here, if only you were here

Except "emphasis" part your understanding is true..

Eğer has no other function than making a conditional sentence to be more easily recognized by the learners. You can ignore this  Persian loan-word as there is no any necessary to add it to a Turkish conditional. You don´t need it even for emphasis. 

Turkish word for conditional is ise and its suffix form is -se/-sa. THis word and its suffix works so perfectly that there really is no room for eğer in any conditional sentence. 

Çalışırsam başarırım, çalışsaydım başarırdım 

Bakarsan görürsün, bakmış olsaydın görürdün

Yaparsa pişman olur, yaptıysa pişman olmuştur

Basarsak yanarız, basmışsa yanmıştır

Uyursanız dinlenirsiniz, uyusaydınız dinlenirdiniz

Giderlerse dönmezler, gidiyorlarsa dönmezler

Trying to make a logical room for eğer in a Turkish conditional is merely an empty work..  

... But, of course, you are free to decide whether or not to add it to a conditional sentence  

Quoting scalpel

 

Quoting Henry

And my basic understanding is that 

eğer (means if), and is used at the start of the sentence or phrase, for emphasis (note that it should still be used with the ´ise´ suffix attached to the verb. It also helps learners recognise a conditional sentence 

 

Except "emphasis" part your understanding is true..

Eğer has no other function than making a conditional sentence to be more easily recognized by the learners. You can ignore this  Persian loan-word as there is no any necessary to add it to a Turkish conditional. You don´t need it even for emphasis. 

Turkish word for conditional is ise and its suffix form is -se/-sa. THis word and its suffix works so perfectly that there really is no room for eğer in any conditional sentence. 

 

... But, of course, you are free to decide whether or not to add it to a conditional sentence  

 

You are a purist!

I have recently noticed that -sin suffix can be used for condition.

Gene gelsin, gene kovarım. = If he/she comes (here) again, I will drive him/her away again.

or should he/she come again, I would drive him/her away again.

Hele bir gelmesin, ne yapacağımı ben bilirim = If he/she doesn´t come (here), I know what to do (about it)

etc.

Let´s say I don´t like a loan-word when there is a Turkish equivalent for.. And I don´t like unnecessary words in my sentences.. Am I a purist? Perhaps.. 

3rd person imperative is widely used in Turkish. It surprises me sometimes to find it in innovative places like wishes. Maybe it´s influence of religious language. Just a guess. In prayers, for instance, the speaker kind of takes a position above the state of affairs and tries to affect how things are going. In my language it is a very archaic, almost dead form which you can only find in religious speech.

Eğer is maybe not needed (thanks for your comment, scalpel, you always bring up something new even if the subject is many times repeated) but it may act as a warning: a condition is about to come. It gives the speaker time to think and form his sentence. There is not too much time to think when you speak Turkish, believe me, everything has to be well sorted out, and without these small breaks the flow of language might be too hasty. Look at your example: it takes me half an hour to analyse the morphology and understand it. What if I didn´t read it but heard it?

Language has a history, a structure and a logic. That´s what we are interested in. But from the grass root level speech is linear. Words follow each other and certain choices lead into other choices. That´s why these conversational turnouts are needed.