I've just checked the dictionary about the meaning of the idiom "concerned with" and I found it as a synonym of "interested in". Then I can use "concerned with" in any place of "interested in", or there are some exceptions that I should know?
For example, if I want to buy a nice car, can I say "I'm concerned with this car"? or "I'm concerned with this girl" and so on?
In the same topic, I'd like to know if I can use "concern with" in the past form without "to be" before. (e.i. instead of using "he was concerned with this car", I would omit the "to be" auxiliary verb and I'd say "He concerned with this car")
Best Answer
No. Remember the following:
The two examples given sound like you're worried about the car and the girl, whereas, without further context, my first impression is that interested in this car means you want to buy it and interested in this girl means you like this girl (or that you want to date her). Also, I think the preferable preposition in either case is about.
Concerned is listed as an adjective, so you cannot drop to be:
You can drop to be when concern functions as a transitive verb.
In either case, something about them worries you.