Never
Not once
Under no circumstances
At no time
Rarely
Only twice
By no means
Barely
Scarcely
Only once in a blue moon
Seldom
Hardly
In no way
On no account
On no condition
Nowhere
No sooner
Not only
Not until
Only if/after/then/when/later
Little
So/ Such
As
Neither/So
In vain
+some conditional sentences (3rd condition)
Tom, one thing you’ll notice is that the majority of these words and expressions are negative or semi-negative.
Even in spoken English, it is quite natural to invert subject and verb if you begin a sentence (or clause) with one of these words/phrases.
I suggest you now give it a whack. Let’s see some more sentences from you. Under no circumstances can this structure be mastered without practicing it.