until的用法

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.