揺れる with に or で


I rarely have any problems with the に and で particles, but I have been a bit
confused since seeing the word 揺れる in a few different sentences.

As far as I know it is ok to say either:

> 旗が風に揺れている

or

> 旗が風で揺れている

Where you could of course replace 旗 with another word like 木 or 電線.

My problem is that I can't tell the difference between these sentences.

To me, at the moment, they both mean **"~ is swaying in the wind"**. But there
must be some difference between these sentences that I am not seeing.

Can anybody tell me the difference in meaning when it comes to the に or で
particles with the word 揺れる?

Any help would be appreciated.




風に揺れる sounds a bit poetic and literary to me. If I'm writing an essay, novel
or poem, I'd write 風に揺れる. I think we usually say 風で揺れる in daily conversations.




I agree with user1016's answer. The slight difference in nuance (for me,
without strong basis) is this:

> Aにゆれる  
>  'swing against A'  
>  'swinging on its own as a reaction to A'
>
> Aでゆれる  
>  'swing {by/due to} A'  
>  'swinging, caused by A'

`に` implies a slight spontaneity whereas `で` implies a strong cause-result
relation.

So when you say `風に揺れる`, it implies that it is an inherent property of a flag
to wave against the wind, and the role of wind is just the trigger. `風でゆれる`
means that the wind is solely responsible for the mechanism of waving.

