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I hold sway in the school.

Is the above grammatically correct? I mean a school principal could always say the above as he is empowered to control all the aspects of the school.

Please tell me whether I am correct.

I hold sway in the class. -> A teacher to his students

I hold sway in the company. -> A manging director of a company to his subordinates.
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It's grammatically correct, but it's unusual to say, in my opinion - especially in the first person.
Most uses of "hold sway" (have dominant influence) that I have seen were in writing and in the third person. It's also frequent with "over". "He held sway over the functioning of the committee".
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Hello Andrei

'Hold sway' often appears in reporting of social or political trends,
especially in headlines, e.g.

'Religious values hold sway in Arkansas'

'Pipe-smoking still holds sway among private detectives'

'Anglo-Saxon monosyllables hold sway over unimaginative
sub-editors'

Otherwise, as has been said, you seldom see or hear it.

MrP

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Comments  
Would it be fine to say the following to my boss at work?

You hold sway over the company.
Andrei, the idiom is rather stilted or antiquated, I feel, and sounds strange spoken; in a sports headline, a history book, a novel or a poem it would be OK.

The boss controls/directs/runs the company.
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Andrei,

NO! Don't say "You hold sway over the company" to your boss! It suggests, hints, or intimates (to me, at least) that maybe he has too much power and influence, or that the company has weakly submitted to or has been intimidated by this influence!

To me a typical use of "hold sway" is

"Although she had been beaten often by her husband, Sandra would not go to the police for help because her husband held her in his sway."

To me it suggests having some sort of psychological influence, even negative, over another person. I would not be comfortable using the expression in the business world.

Jim
 MrPedantic's reply was promoted to an answer.