You are to stay until/till your mother comes back. 你得等到你妈妈回来。
The meeting was put off until ten o'clock. 会议推迟到十点钟。
The villagers didn't realize how serious the pollution was until all the fish died in the river.
→Not until all the fish died in the river did the villagers realize how serious the pollution was.(倒装句)
He didn't go to bed until his mother came back.
→It was not until his mother came back that he went to bed.(强调句)
Not until he failed in the exam did he realize that he had wasted much time playing computer games.
Not until his son came back from school did he go to bed.友情提醒：本文来自教育资源库收集与整理，特别感谢原作者！