until的用法
- 延续性动词 + until + 短暂动词/时间点
Wait until he comes back.
I will be away from my office until next Tuesday.
We will stay here until it stops raining. - 短暂动词(否定式) + until + 短暂性动词 / 时间点
He didn't leave the office until his boss came back.
The little boy didn't smile until he saw his mother.
not until的四种结构
- 正常结构
The little boy didn't smile until he saw his mother. - until置于句首
Until he saw his mother,the little boy didn't smile. - 倒装结构
Not until he saw his mother,did the little boy smile. - 强调结构
It was not until he saw his mother that the little boy smiled.
