articulate vs formulate

articulate is an adjective but formulate is not an adjective.

Word	Noun	Adjective	Verb	Adverb
articulate	No	Yes	Yes	No
formulate	No	No	Yes	No

As verbs, articulate and formulate are synonyms defined as:

Other synonyms of articulate include give voice, phrase, word.

articulate (adjective)	formulate (adjective)
expressing yourself easily or characterized by clear expressive language
consisting of segments held together by joints

articulate (verb)	formulate (verb)
speak, pronounce, or utter in a certain way	put into words or an expression
express or state clearly	elaborate, as of theories and hypotheses
put into words or an expression	come up with (an idea, plan, explanation, theory, or principle) after a mental effort
provide with a joint	prepare according to a formula
unite by forming a joint or joints