concern vs pertain

concern is a noun but pertain is not a noun.

Word	Noun	Adjective	Verb	Adverb
concern	Yes	No	Yes	No
pertain	No	No	Yes	No

As verbs, concern and pertain are synonyms defined as:

Other synonyms of concern include bear on, come to, have to do with, refer, relate, touch, touch on.

concern (noun)	pertain (noun)
something that interests you because it is important or affects you
something or someone that causes anxiety; a source of unhappiness
a feeling of sympathy for someone or something
an anxious feeling
a commercial or industrial enterprise and the people who constitute it

concern (verb)	pertain (verb)
be relevant to	be a part or attribute of
be on the mind of	be relevant to