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, not, never, seldom, little, hardly, at no time, in no way, not until… 等，其实任何含no的，只要词组放在首位就要倒装。例如：
Never have I seen such a performance.
Nowhere will you find the answer to this question.
Under on condition will we give in to the differenties.
Not until the child fell asleep did the mother leave the room.
当Not until引出
主从复合句，主句倒装，
从句不倒装。
注意： 如否定词不在句首不倒装。
I have never seen such a performance.
The mother didn't leave the room until the child fell asleep.
再者是 Not only…but also, Hardly/Scarcely…when, No sooner… than，例如：
Not only did he refuse the gift, he also severely criticized the sender.
Hardly had she gone out when a student came to visit her.
No sooner had she gone out than a student came to visit her.
典型例题
No sooner___ than it began to rain heavily.
A. the game began B. has the game begun
C. did the game begin D. had the game begun
答案D. 以具有否定意义的副词放在句首时，一般采用
倒装句(谓语前置)。这类表示否定意义的词有never, seldom, scarcely, little, few, not, hardly, 以及not only…but (also), no sooner…than, hardly… when
scarcely… when 等等。
注意：只有当Not only… but also连接两个分句时，才在第一个分句用倒装结构。如果置于句首的Not only… but
also仅连接两个并列词语，不可用倒装结构。
Not only you but also I am fond of music.
还有就是句中有neither, nor的，也可作部分倒装 ，表“也不”，例如：
If you won't go, neither will I.你不去，我也不去。
有个值得注意的地方是，当not/neither……nor同时出现构成句子时，此时句子是前后都要倒装的。例如：Not could the patient eat, nor could he drink.这个病人既不能吃也不能喝。
不知道这样够不够详细，不过我觉得要理解还是在题目中找找感觉比较好。