These structureThe way in which the parts of a sentence, clause or expression are arranged. E.g.: make somebody + infinitive in "The teacher made me rewrite the composition."s are used mainly in formalNot belonging to colloquial or everyday speech; official. E.g.: I demand that Mr Smith call the person on whom the committee has decided. or literary language for rhetorical effect.

Never (before) have we faced such a challenge! (= We have never faced such a challenge!)

Rarely did she understand what the conversation was about. (= She rarely understood what the conversation was about.)

Little did Peggy know where Al had gone. (= Peggy didn’t know at all where Al had gone.)

Under no circumstances are you allowed to disturb the pilots. (= You are not allowed to disturb the pilots under any circumstances. / You are allowed to disturb the pilots under no circumstances.)

On no condition will the company bear responsibility for lost property. (= The company will bear responsibility for lost property on no condition. / The company will not bear responsibility for lost property on any condition.)

Not only did he exceed the speed limit, but he had also consumed alcohol. (= He not only exceeded the speed limit but he had also consumed alcohol.)

Not only did he exceed the speed limit, but he had consumed alcohol too. (= He not only exceeded the speed limit but he had consumed alcohol too.)

Not only were you late, but you didn’t even have a good excuse. (= You were not only late, but you didn’t have a good excuse either.)

HARDLY, SCARCELY, BARELY, NO SOONER
Partial inversion after negative adverbials ONLY AFTER, ONLY IF, ONLY IN THIS WAY etc., NOT UNTIL