This interesting conjunction takes on different roles according to the situation. But it is not to be confused with the suffix -ki, whose purpose and meaning are entirely separate.

1. that, who, which
2. so that, such that
3. what do you know, would you believe it, son of a gun
4. seeing that, considering that
5. as, though
6. when
7. ..., I wonder?
8. indicates frustration, disapproval, doubt, or anxiety
9. used for emphasis

1. Bir şey yapmadım kipişmanlık duyayım. I haven´t done anythingthat I should feel sorry about. 
   Click to see Politically Incorrect illustration of kiusage...
2. Öyle ucuz ki herkes alabilir. It´s so cheap thateveryone can afford it.
3. Eve geldim ki kapı duvar. I came home[alone], but [would you believe it?] nobody answered the door.
4. Adam üşümüş kipaltosunu giymiş. The man must have been cold seeing that he put on his coat.
5. Cevap vermeseydi bile -- ki verdi -- iş olacağına varırdı. Even if he hadn´t replied -- though he did -- the thing wouldn´t have turned out any differently.
6. Henüz uykuya dalmıştıki, bir patlama oldu. I´d just dropped off to sleepwhen something exploded.
7. Bilmem ki ne yapsam?What should I do, I wonder?
8. O bana inanmaz ki! She won´t believe me [so why should I speak to her?]...
9. Öyle güzel ki! It´s morebeautiful than I can say!