`11` If I had enough money, I would buy it.

`13` If I knew all of the details, I could explain further.

`14` If I weren't too busy now, I could help you.

`15` If you don't keep silent, you won't understand the lesson.

`16` Unless it stops raining, we can't go out.

`-` ĐK1 : If + hiện tại đơn , S + will + V + O...

`-` ĐK2 : If + quá khứ đơn, S + would + V + O...

`11.` If I had enough money, I would buy it.

`13.` If I knew all of the details, I could explain further.

`14.` If I weren't too busy now, I could help you.

`15.` If you don't keep silent, you won't understand the lesson.

`16.` Unless it stops raining, we can't go out.

`-` Câu điều kiện loại 1: If + HTĐ, S + will/can/may/... + (not) + V(bare)

`-` Unless = If not `->` Mệnh đề chứa "Unless" phải luôn ở dạng khẳng định

`-` Thì HTĐ: `(-)` S + don't/doesn't + V(bare)

`-` Câu điều kiện loại 2: If + QKĐ, S + would/could/might + (not) + V(bare)

`-` Thì QKĐ: 

`+` Với động từ thường: `(+)` S + V2/ed 

`+` Với động từ tobe: `(-)` S + wasn't/weren't + N/Adj