ADJ

considerable, deep, grave, great, major, serious
growing, mounting
common, widespread
national, public
public concern about increased taxes

VERB + CONCERN

feel
He felt some concern for her safety
express, show, voice
cause
The lack of firefighting equipment has caused concern

PREP

in sb's ~
She forgot her own worries in her concern for him
out of ~
~ about/over
She expressed her deep concern about conditions at the factory
~ for
Out of concern for her health, we suggested she take a week off work

PHRASES

be of (no) concern to sb
Increased use of drugs is of great concern to parents
(a) cause for concern
The president's health is giving serious cause for concern
a lack of concern
I was surprised by her lack of concern
a matter of concern
Stress at work is a matter of concern to staff and management

ADJ

chief, main, major, overriding, paramount, primary
What are your main concerns as a writer?
common
a common concern for new parents

PHRASES

be none of sb's concern
How much we paid is none of your concern

ADV

directly

PREP

in
Everyone who was directly concerned in (= had some responsibility for) the incident has now resigned

ADV

a lot, really
It really concerns me that he doesn't eat properly
slightly