"the safety of the ship is the captain's concern"
"care had aged him"
"they hushed it up out of fear of public reaction"
"She felt strong concern for those less fortunate"
"New York traffic is a constant concern"
"it's a major worry"
"he bought his brother's business"
"a small mom-and-pop business"
"a racially integrated business concern"
"There were lots of questions referring to her talk"
"My remark pertained to your earlier comments"
"I worry about the second Germanic consonant shift"
He was concerned to hear of her ill health.
to hear表示原因
He was concerned to improve her health.
to improve表示目的
He was concerned about the matter.
他为了这件事关心或担心。
He was concerned in the matter.
他参与了这件事。
He was concerned with the matter.
他跟这件事有关。
The story is concerned with a national hero.
这个故事牵涉到一个民族英雄。