probably vs likely

probably is not an adjective while likely is an adjective.

Word	Noun	Adjective	Verb	Adverb
probably	No	No	No	Yes
likely	No	Yes	No	Yes

As adverbs, probably and likely are synonyms defined as:

Other synonyms of probably include belike, in all likelihood, in all probability.

probably (adjective)	likely (adjective)
	has a good chance of being the case or of coming about
	within the realm of credibility
	expected to become or be; in prospect

probably (adverb)	likely (adverb)
with considerable certainty; without much doubt	with considerable certainty; without much doubt
easy to believe on the basis of available evidence