shop clerk vs shop assistant

shop clerk and shop assistant both are nouns.

Word	Noun	Adjective	Verb	Adverb
shop clerk	Yes	No	No	No
shop assistant	Yes	No	No	No

As nouns, shop clerk and shop assistant are synonyms defined as:

Other synonyms of shop clerk include clerk, salesclerk.

shop clerk (noun)	shop assistant (noun)
a salesperson in a store	a salesperson in a store