keep on vs keep up

keep on and keep up both are verbs.

Word	Noun	Adjective	Verb	Adverb
keep on	No	No	Yes	No
keep up	No	No	Yes	No

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

keep on: allow to remain in a place or position or maintain a property or feature
keep up: lengthen or extend in duration or space

Other hypernyms of keep on include prolong, sustain.

keep on (verb)	keep up (verb)
allow to remain in a place or position or maintain a property or feature	prevent from going to bed at night
	keep informed
	maintain a required pace or level
	keep in safety and protect from harm, decay, loss, or destruction
	lengthen or extend in duration or space