change form vs extend

change form and extend both are verbs.

Word	Noun	Adjective	Verb	Adverb
change form	No	No	Yes	No
extend	No	No	Yes	No

As verbs, extend is a hyponym of change form; that is, extend is a word with a more specific, narrower meaning than change form:

change form (verb)	extend (verb)
assume a different shape or form	extend one's limbs or muscles, or the entire body
	thrust or extend out
	extend in scope or range or area
	lengthen in time; cause to be or last longer
	continue or extend
	expand the influence of
	increase in quantity or bulk by adding a cheaper substance
	prolong the time allowed for payment of
	use to the utmost; exert vigorously or to full capacity
	open or straighten out; unbend
	extend or stretch out to a greater or the full length
	cause to move at full gallop
	offer verbally
	make available; provide
	span an interval of distance, space or time
	reach outward in space
	stretch out over a distance, space, time, or scope; run or extend between two points or beyond a certain point