sound out vs articulate

sound out is not an adjective while articulate is an adjective.

Word	Noun	Adjective	Verb	Adverb
sound out	No	No	Yes	No
articulate	No	Yes	Yes	No

As verbs, sound out and articulate are synonyms defined as:

Other synonyms of sound out include enounce, enunciate, pronounce, say.

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

sound out (verb)	articulate (verb)
try to learn someone's opinions and intentions	speak, pronounce, or utter in a certain way
speak, pronounce, or utter in a certain way	express or state clearly
	put into words or an expression
	provide with a joint
	unite by forming a joint or joints