[Beatrix]

is there some rule when we should use them or are they completely interchangeable?

thank you guys in advance

[susan53]

Do you remember posting a question on bored by/with some time ago Beatrix? If you look back at those answers I think you'll find it's the same case here. I think there are two things going on when by/with seem to be interchangeable.

1. When there's a passive involved, it's generally a matter of "agent" or "instrument".

By expresses the agent of the action and with the instrument. That's clear in a sentences like He was killed by a hunter/He was killed with a shotgun.

But sometimes we see the "instrument" as being the the "agent" - so, He was killed by a random bullet. Here, we're not interested in the real, human, agent, so see the bullet itself as the agent.

2. When there's an emotional reaction involved we can still talk about the agent using "by"... I was bored/impressed/surprised by the film

or alternatively we can use with/at to express the cause of the reaction - at tends to be used with a noun that really describes an action/event I was surprised at his behaviour / I was surprised at the way the film ended and with when it's a person or object I was delighted with the present / I was bored with the film.

Well, that's what the Communicative Grammar (Leech and Svartvik, Longman) says, and it works in those examples. But it doesn't explain why you can be "bored with" a film, but you can't be "*surprised with" a film.

So no, they aren't always completely interchangeable with every adjective. But I can't quite put my finger on why ... Next time I get my hands on some different grammars, I'll see what they say.

[Beatrix]

thanks a lot, sue

the precise sentence is : I was impressed with your lectures.
That sounds weird to me, I thought BY suited it better

[mesmark]

I have been thinking about this each time I stop by.

It seems to me "with" has more of a feel of character or comparison where "by" has more of a naming the agent feeling. That doesn't make much sense, but I thought I'd join in on the topic.

I was impressed with him.
- he did a better job than I thought he could do or better than most would do


I was impressed by him.
- who impressed me? --> he did.


I was impressed with your lectures.
- they were better than I expected or better than most

I was impressed by your lectures.
- some data or information in the lecture was impressive


Anyway, in most cases they seem interchangeable to me. Those are just my thoughts on the nuances of the two.

[Beatrix]

thanks guys