know apart vs subtilize

know apart and subtilize both are verbs.

Word	Noun	Adjective	Verb	Adverb
know apart	No	No	Yes	No
subtilize	No	No	Yes	No

As verbs, subtilize is a hyponym of know apart; that is, subtilize is a word with a more specific, narrower meaning than know apart:

know apart (verb)	subtilize (verb)
recognize or perceive the difference	make more subtle or refined
	make (senses) more keen
	mark fine distinctions and subtleties, as among words