Interested "in" or "by" something? [closed]

I just wanted to know if the grammatically correct form is "I am interested in something" or "I am interested by something".

Thanks

Both are used, though in slightly different contexts.

You might say for example I am interested IN history.

(You could say I am interested BY history, but it would be unusual and not as idiomatic.)

However one might say I was interested BY the way the man was walking or perhaps ...by the way the words were written on the card.

You might use 'interested by' to refer to something which had caught your attention. Again one might also say 'interested in'. In these circumstances either would be idiomatic.

In addition to WS2's answer, I would like to add that interested by can be used when a certain object or person can somewhat actively interest you:

• The professor interests me because of his lecture(, so I am interested by him)

But:

• I am interested in the professor

Sounds like the professor is not consciously doing anything to spark your interest, therefore, you take interest in him.

So if you can easily turn it around and say Some object/thing/person interests me, then it is probably okay to say interested by. If you are the person who draws initial interest (because of less apparent reasons), say interested in.