1) 句首為否定或半否定的詞語(yǔ)，如no, not, never, seldom, little, hardly, at no time, in no way, not until… 等。
Never have I seen such a performance.
Nowhere will you find the answer to this question.
Not until the child fell asleep did the mother leave the room.
當(dāng)Not until引出主從復(fù)合句，主句倒裝，從句不倒裝。
注意： 如否定詞不在句首不倒裝。
I have never seen such a performance.
The mother didn't leave the room until the child fell asleep.
典型例題
1) Why can't I smoke here?
At no time___ in the meeting-room
A. is smoking permitted B. smoking is permitted
C. smoking is it permitted D. does smoking permit
答案A. 這是一個(gè)倒裝問(wèn)題。當(dāng)否定詞語(yǔ)置于句首以表示強(qiáng)調(diào)時(shí)，其句中的主謂須用倒裝結(jié)構(gòu)。 這些否定詞包括no, little, hardly, seldom, never, not only, not until等。本題的正常語(yǔ)序是 Smoking is permitted in the meeting-room at no time.
2) Not until the early years of the 19th century ___ what heat is.
A. man did know B. man know C. didn't man know D. did man know
答案D. 看到Not until…的句型，我們知道為一倒裝句，答案在C，D 中選一個(gè)。
