部分倒装是指将谓语的一部分如助动词或情态倒装至主语之前。如果句中的谓语没有助动词或情态动词，则需添加助动词do, does或did，并将其置于主语之前。

　　1)　句首为否定或半否定的词语，如no, never, seldom, little, hardly, at no time, in no way, not until… 等。

　　例如：　　Never have I seen such a performance.

　　我从未看到过这样的表演。

　　Not until the child fell asleep did the mother leave the room.

　　直到孩子睡着母亲才离开房间。

　　注意：

　　① 如否定词不在句首不倒装。

　　例如： I have never seen such a performance.

　　The mother didn't leave the room until the child fell asleep.

　　② 当Not until引出主从复合句，主句倒装，从句不倒装。

　　例如：　 Not until the child fell asleep did the mother leave the room.