If you say someone is concerned, it means that person is worried:
▶️ I’m concerned about my son – he’s not getting good grades in school.
▶️ I live in a big city, and my mother is concerned for my safety.
▶️ We’re concerned that we won’t be able to finish the project in time.
You can also say “it concerns me” to talk about something that worries you:
▶️ I’ve had a stomachache for the past three days. It’s starting to concern me.
▶️ It concerns me that the teachers don’t seem interested in helping the
students.
The noun concern means “a worry”:
▶️ Sheila is going to marry an ex-convict. Her father has deep concerns about
the relationship.
▶️ There is growing concern that the country’s economy may enter into a
recession.
▶️ I have a few concerns about this contract – it doesn’t seem like a good deal.
The word concerning means something completely different – it means “relating
to” or “about.”
▶️ Please visit your local bank for more information concerning your account.
“Concerning” is a bit formal – in everyday English we typically use “about”:
▶️ Formal: There were a number of questions concerning the new program.
▶️ Informal: There were a number of questions about the new program.
When concerned is used as a past participle (after the subject), it means “involved”
or “affected”:
▶️ There was a big fight at the bar. The police talked with everyone concerned.
(Everyone involved in the incident)
▶️ After a defect was discovered in the manufacturing process, the products
concerned were recalled. (The products affected by the defective process)