impressed 'with'? or impressed 'by'?

They both strike me as idiomatic. It seems to me that I've heard both many times.

CJ

Yes, "with" means "by," meaning the agent/cause (doing the action of impressing in this case), in some contexts.

I'd suggest to look (buy!) at the Cobuild Dictionary for Advanced Learners. It would clarify many of your non-native issues.

generally, 'by' is used for the agent or the doer of the action while 'with' is used for the tool. So, when we are using the passive voice, we can say, "I am impressed by you", otherwise, we can say, "You impress me with your honesty".

Anonymous, when we are using the passive voice, we can say, "I am impressed by you",

As CJ said some years ago, "They both strike me as idiomatic. It seems to me that I've heard both many times."

I slightly disagree here, as "I am impressed by you" is not a passive!!! Impressed is merely the past participle, used as an adjective.
"... After past participles that are used like adjectives, we prefer other prepositions [than by]." (Swan, Michael. Practical English Usage. Oxford, OUP 1995, page 404)
Best
Angie

AnonymousI slightly disagree here, as "I am impressed by you" is not a passive!!! Impressed is merely the past participle, used as an adjective.

The use of 'by' suggests that it is a passive form.
"... After past participles that are used like adjectives, we prefer other prepositions [than by]." (Swan, Michael. Practical Englis