formulate vs articulate

formulate is not an adjective while articulate is an adjective.

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

As verbs, formulate and articulate are synonyms defined as:

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

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

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