Tom yeni bilgisayarın ne kadara mal olacağını kesin olarak bilmiyordu.
- Tom didn't know for certain how much the new computer would cost.
Tom nereye gitmesi gerektiğini kesin olarak bilmiyordu.
- Tom didn't know for certain where he should go.
For certain.
... don't want to laugh, because I'm quite certain that ...
... families. We have some ideas about that, but that’s relatively less certain. ...