部分倒裝是指將謂語的一部分如助動詞或情態倒裝至主語之前。如果句中的謂語沒有助動詞或情態動詞，則需添加助動詞do, does或did，並將其置於主語之前。
1)句首爲否定或半否定的.詞語，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Not until引出主從複合句，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 ing is permitted
C. smoking is it smoking permit
答案A. 這是一個倒裝問題。當否定詞語置於句首以表示強調時，其句中的主謂須用倒裝結構。 這些否定詞包括no, little, hardly, seldom, never, not only, not until等。本題的正常語序是 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，我們知道爲一倒裝句，答案在C，D 中選一個。
改寫爲正常語序爲，Man did not know what heat is until the early years of the 19th. 現在將not提前，後面就不能再用否定了,否則意思就變了。