shop vs tell on

shop is a noun but tell on is not a noun.

Word	Noun	Adjective	Verb	Adverb
shop	Yes	No	Yes	No
tell on	No	No	Yes	No

As verbs, shop and tell on are synonyms defined as:

Other synonyms of shop include betray, denounce, give away, grass, rat, shit, snitch, stag.

shop (noun)	tell on (noun)
a course of instruction in a trade (as carpentry or electricity)
a mercantile establishment for the retail sale of goods or services
small workplace where handcrafts or manufacturing are done

shop (verb)	tell on (verb)
give away information about somebody	produce an effect or strain on somebody
do one's shopping	give away information about somebody
shop around; not necessarily buying
do one's shopping at; do business with; be a customer or client of