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Can someone explain the structure of the following sentence?

Not till he got home did he realise that he had lost his mobile.

Why we are doing inversion here ?

marked as duplicate by Cascabel, marcellothearcane, Edwin Ashworth, Community Jul 30 '17 at 3:10

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  • I am sorry for tag – NullPoiиteя Jul 29 '17 at 15:32
  • I assume you wrote the sentence, since it has no attribution. So why did you use inversion? – Cascabel Jul 29 '17 at 15:36
  • No i was doing practice and came across this sentence in book – NullPoiиteя Jul 29 '17 at 15:38
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    If you are doing a practice surely there is some sort of explanantion in the book. What part did you not understand? You need to show some research. – Cascabel Jul 29 '17 at 15:40
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    Don't pay attention to explanations in practice books. Indeed, many of the sentences in English practice books are made up by non-native speakers who don't understand English grammar (or often, English). So many of the sentences are themselves ungrammatical. In this case the inversion is licensed by the fact that the inverted material is negative and negates the main clause -- i.e, he didn't realize he'd lost his mobile until he reached home. – John Lawler Jul 29 '17 at 15:51