English — Inversion after negative adverbials
When a negative or restrictive adverbial is placed at the front of a clause for emphasis, English uses subject-auxiliary inversion, exactly as in a question: Never have I seen such a mess.
How it works
After a fronted negative or restrictive adverbial, put the auxiliary before the subject. If there is no auxiliary, add do/does/did: Never do I complain. With perfect tenses the pattern is Hardly had I arrived when it started; Not only does she sing, she also writes the songs; No sooner had he left than the phone rang.
Examples
| Inverted sentence | Neutral order (meaning) |
|---|---|
| Never have I seen such courage. | I have never seen such courage. |
| Hardly had I sat down when the phone rang. | As soon as I sat down, the phone rang. |
| Not only does he lie, but he also cheats. | He not only lies, he also cheats. |
| Only then did I understand the problem. | I understood the problem only then. |
| No sooner had we left than it started to rain. | We had only just left when it started to rain. |
| Little did she know what awaited her. | She had no idea what awaited her. |
| Under no circumstances should you sign this. | You should not sign this under any circumstances. |
Good to know
Invert only when the negative adverbial modifies the whole clause and is fronted. If "only" or a negative simply modifies a subject noun phrase, keep normal order: Only a few people came (not "Only a few people did come"). This inversion is formal or literary; in everyday speech the neutral order is more natural.