separate vs tell

separate is a noun but tell is not a noun.

Word	Noun	Adjective	Verb	Adverb
separate	Yes	Yes	Yes	No
tell	No	No	Yes	No

As verbs, separate and tell are synonyms defined as:

Other synonyms of separate include differentiate, distinguish, secern, secernate, severalise, severalize, tell apart.

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

Other hypernyms of separate include differentiate, distinguish, secern, secernate, separate, severalise, severalize, tell apart.

separate (noun)	tell (noun)
a garment that can be purchased separately and worn in combinations with other garments
a separately printed article that originally appeared in a larger publication

separate (adjective)	tell (adjective)
independent; not united or joint
standing apart; not attached to or supported by anything
separated according to race, sex, class, or religion
have the connection undone; having become separate

separate (verb)	tell (verb)
become separated into pieces or fragments	discern or comprehend
divide into two or more branches so as to form a fork	mark as different
arrange or order by classes or categories	let something be known
mark as different	narrate or give a detailed account of
move or break apart	give instructions to or direct somebody to do something with authority
force, take, or pull apart	give evidence
divide into components or constituents	express in words
go one's own way; move apart	inform positively and with certainty and confidence
make a division or separation
treat differently on the basis of sex or race
separate into parts or portions
discontinue an association or relation; go different ways
act as a barrier between; stand between