tell on vs inform

tell on and inform both are verbs.

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

As verbs, inform is a hypernym of tell on; that is, inform is a word with a broader meaning than tell on:

tell on (verb)	inform (verb)
produce an effect or strain on somebody	give character or essence to
give away information about somebody	impart knowledge of some fact, state of affairs, or event to
	act as an informer