`1` Unless he has  to work, he won't come 

`->` Câu đk loại  1

Unless= If...not 

`2` He's so short that he can't play volleyball 

`->` S + be + so + adj+ that + S + can't / couldn't+ V + O : quá đến nỗi mà 

`3`  I would rather you delivered the sofa on Saturday .

`->` Would rather + S + Ved / V2 + O 

He will come  if he doesn’t have to work .
Unless he has to work, he will come. 

Unless= If not: Nếu không
He is too short to play basketball.
He’s so short that he can't play basketball.

so adj that clause: quá như nào đó để làm gì
38.I want you to deliver the sofa on Saturday.
I  would rather you delivered the sofa on Saturday.

would rather sb + Ved/c2: Yêu cầu ai làm gì