为了强调、突出等词语的目的而颠倒原有语序的句式叫做倒装句。在倒装句中，颠倒了的成分可以恢复原位而句意基本不变，句法成分不变。当否定副词或副词短语、only + 副词或 only + 介词短语置于句首时，句子用部分倒装。常见的可用倒装的否定副词或副词短语主要有以下一些，只要记住它们，就能掌握大部分的倒装用法了。
这几个否定副词常与 when 搭配，当它们置于句首时，句子用部分倒装，而且倒装发生在主语和助动词之间，通常此时主句用过去完成时，when 从句用一般过去时，意为“刚…，就…”，表示两件事接踵而至。Hardly had I got into bed when the telephone rang.Hardly had I arrived home when my phone rang.Scarcely had I got off the bus when it crashed into the back of a car.Scarcely had she finished reading when she fell asleep.Barely had they won the match when the coach had a heart attack.Barely had Jack reached the place when Jim started arguing with him.注意：当 hardly，scarcely 或 barely 置于 any 及其组合词如 anyone，anything，anybody 或名词短语等前面且置于句首时，句子不用倒装结构，例如：Hardly anyone passed the exam.Scarcely a day goes by when they don't see or talk to each other.
二、never，seldom，rarely，little，nowhere，…这几个否定或近似否定的副词置于句首时，句子的主语和助动词要倒装。Never have we faced such a challenge!Seldom have I seen such beautiful work.Seldom do we see such an amazing display of dance.Rarely will you hear such beautiful music.Little did she understand what the conversation was about.Nowhere have I ever had such bad service.
三、only then，only later，only recently，only in this way，only on one point，only now，…
Only + 副词或 only + 介词短语，置于句首时，句子的主语和助动词要倒装。Only then did I understand why the tragedy had happened.
3. only recently
Only recently have I become convinced that we made the right decision in moving.
直到最近，我才肯定了搬家的决定是正确的。
4. only in this way
Only in this way could John earn enough money to survive.
只有这样约翰才能挣到足够的钱来生存。
5. only on one point
Only on one point do I agree with you.
只有一点，我同意你的说法。
6. only now
Only now can I understand what really happened.
Not only … but also … 前后连接两个句子时，not only 后的句子要用部分倒装，但 but also 后的分句不用倒装。Not only does he love chocolate and sweets but he also smokes.
跟 hardly/scarcely/barely … when 意思一样，no sooner 常跟 than 搭配，置于句首时，句中的主语和助动词要倒装，通常主句用过去完成时，从句用一般过去时，意为“刚…，就…”，表示两件事接踵而至，其中 sooner 是 soon 的比较级。No sooner had we arrived home than the police rang the doorbell.No sooner had the company launched its new product than it went bankrupt.No sooner did I arrive at the station than the train came.No sooner did we hear the noise than we rushed to the spot.
六、in no way，on no account，on no condition，under no circumstances
1. in no way，意为“决不，一点也不”
In no way do I agree with what you're saying.
我决不同意你说的话。
In no way can this government deny its guilt.
这个政府决不能否认自己有罪。
2. on no account，意为“决不，一点也不”
On no account should you do anything without asking me first.
你决不能不先问我就做任何事。
On no account will I compromise my ideals.
我决不会放弃我的理想。
3. on no condition，意为“决不，无论如何不”
On no condition will the company bear responsibility for lost property.
4. under no circumstances，意为“决不，无论如何不”
Under no circumstances are you allowed to disturb the pilots.
Not once 或 not + 其他成分，意为“…也不…”，例如：Not once did she look at me at the party.Not in a million years will I go back to that hotel.
Not until I filled my glass did I notice that it was broken.2. not since，意为”自从…以来，从未…“Not since Lucy left college had she had such a wonderful time.3. only after，意为”只有…之后才…“Only after I'd seen her flat did I understand why she wanted to live there.Only after finishing your homework can you play.
4. only when，意为”只有当…，才…”
Only when we'd all arrived home did I feel calm.
只有当我们都到家的时候，我才感到平静。
Only when I myself became a parent did I realize the value of my parents' advice.
只有当我自己为人父母时，我才意识到父母建议的价值。
5. only if，意为“只有…，才…”
Only if everybody agreed would I accept this position.Only if we invest more money can we save the company.
