get onto vs cotton on

get onto and cotton on both are verbs.

Word	Noun	Adjective	Verb	Adverb
get onto	No	No	Yes	No
cotton on	No	No	Yes	No

As verbs, get onto and cotton on are synonyms defined as:

get onto and cotton on: understand, usually after some initial difficulty

Other synonyms of get onto include catch on, get it, get wise, latch on, tumble, twig.

get onto (verb)	cotton on (verb)
understand, usually after some initial difficulty	understand, usually after some initial difficulty