Be concerned about sth/sb = Used after a linking verb such as be; If you are concerned about something, you are worried about it.
Be concerned with sth/sb = To be related to a particular thing or person; if a piece of information, statement or speech is concerned with a subject, it deals with it.
Grandma has been concerned about Jack lately.
The Prime Minister was concerned about the level of corruption in the country.
Mr Harry has always been concerned about the welfare of his employees.
Mother is getting concerned about Susan because she has been busy on her computer all day.
I’m sure everything will go as planned — don’t be so concerned about it.
This statement of the minister is concerned with recent walk-outs by the opposition.
This exercise is concerned with grammar.
We would like to have the opinion of all concerned before embarking on this new business venture.
Be Careful! Do not say that a piece of information, statement or speech is concerned about a subject.
This statement of the minister is concerned about recent walk-outs by the opposition. ✗
Be careful! When the adjective ‘concerned’ is used before a noun, its meaning changes. Here, it is used to refer to people or things involved in a situation that we have just mentioned.
Sally has already begun working on the projects concerned.
We also use ‘concerned’ with the pronouns all, everyone, and everybody:
It is hereby informed to all concerned.
There was manifest relief among all the concerned at the decision not to shut down the unit.
Also, concerned is used where the sense is so far as that goes; as or so far as that is concerned.
Take no chances where human safety is concerned.