Correct spelling, explanation: the origin of concern can be tracked in the Latin word concernere, which combined the words con and cernere. The second word could be translated as discern. Before concern started to look the way we know it today, it was also affected by the French word concerner. Finally, in the Middle Ages, concern appeared in the English language too.

Definition of concern:
1. verb – to be worried about something or to involve somebody,
My marriage problems shouldn’t concern you so much, I’m an adult and I can handle it myself.
2. noun – a feeling of being worried,
We can observe widespread concern about increasing prices and inflation.
3. noun – a company,
It’s a huge American concern, which has taken over most of the local businesses.

Expression and phrases with concern:
A few popular expressions and phrases with concern are: express concern, cause concern, and deep concern.
A few parents expressed their concern about the lack of motivation to study among young learners.
The poor state of the plane caused my concern when I was boarding, but luckily we landed safely.
His mother feels deep concern about his problems at school and is worried that he will be expelled.

Incorrect spelling, explanation: despite the fact that concern is a short word, it causes some spelling problems. Most probably, it is the pronunciation to blame as the -c letter in the middle is pronounced as -s and because of that concern is often misspelled as consern, which is wrong.