Question

17．她直到媽媽回來才停止彈琴．
?Shedidn't stop playing the piano until her mother came back．

Answer 1

分析 didn't stop playing the piano until．

解答 答案：didn't stop playing the piano until．這里是說過去的事情用一般過去時，表示直到…才…用not…until…，表示停止正在做的事情用stop doing sth，stop是實意動詞，借助于助動詞did加上not，故didn't stop，彈鋼琴play the piano，故答案是didn't stop playing the piano until．

點評 not…until指的是"直到…才"的意思，如 I did not go home until my mother called me．
我直到我媽媽打電話給我才回家．
當Not until位于句首時，句子要倒裝．其結構為：Not until+從句/表時間的詞+助動詞+（主句）主語+謂語+．如：
①Not until the teacher came in did the students stop talking．直到老師進來學生們才停止講話．
②Not until next week will the sports meet be held．直到下周才開運動會．