=>

9. It was brave of him to stay in the old house alone the whole night.

-> it is/was brave of sb to V ~ ai thật dũng cảm khi (làm gì)

10. They used to go to school by bike when they were young.

-> used to V : đã từng

I suggest taking a course in photography.

-> suggest Ving : đề nghị, gợi ý

$9$ `:` It was brave of him to stay in the old house alone the whole night.

`->` It `+` be `+` brave of sb to `+` V_inf `+` O `:` Ai đó thật dũng cảm khi làm gì

$10$ `:` They used to go to school by bike when they were young.

`->` Used to `+` V_inf `:` Đã từng làm gì đó

$11$ `:` I suggest taking a course in photography.

`->` Suggest `+` V`-`ing `:` Đề nghị , gợi ý làm gì đó