Incorrect spelling, explanation: concern is a word with a relatively simple spelling, but probably because of the pronunciation of the word, a lot of English users think that there is a -s letter in the middle of the word instead of -c. Therefore, a common spelling mistake made in concern is consern, which is incorrect.

Correct spelling, explanation: concern is a word that entered English in the times of late Middle English. Concern derives from the Latin form concernere, which actually joined two Latin words – con and cernere – with the latter one meaning discern. Before concern entered English, it was also influenced by a French form concerner. In modern English concern functions as a noun and as a verb.

Definition of concern:
1. verb – to worry about something,
His harsh words shouldn’t concern you so much, you know that he always acts like that when he’s angry and later regrets and apologizes.
2. verb – to involve someone, to be important to someone,
Solving the problem of global warming should concern all people, not only environmentalists.
3. noun – a nervous feeling, which makes you worried,
My concern is growing as I haven’t heard from him for over a week.
4. noun – business,
They have been running this family concern for over a decade and they’re still developing.

Collocations with concern:
A few common collocations with concern are: be of concern to someone, a lack of concern, and a matter of concern.
Addictions to the Internet and computer games are becoming more and more common among kids, which is of great concern to parents.
Her lack of concern when her husband disappeared was a bit suspicious.
Using or selling drugs at school is a matter of concern to both teachers and students.