Inversions

[Bernard M]

Hello,

I have two questions about inversions in English:
1- is the inversion mandatory in the cases indicated or just a style formula? 
2 - Is the list of cases cited exhaustive or are there other expressions of this type (other negative adverbial expressions or other frequency adverbs ...)?

Thank you for your help.

Have a nice day.

[Minoo]

Hello Bernard,

1. If you start your sentence with the negative expression in order to emphasise it, inversion is mandatory. Saying' Never I had heard this.' is wrong. You must say: 'Never had I heard this.' However, you always have the choice of moving the negative expression to the middle of the sentence as long as you don't mind removing the emphasis.

2. I cannot claim my list to be exhaustive, but I have made sure that the most common expressions are listed. 

[Bernard M]

Thank you very much, Minoo. Your answer is very clear to me.