speaking vs articulate

speaking is a noun but articulate is not a noun.

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

speaking (noun)	articulate (noun)
delivering an address to a public audience
the utterance of intelligible speech

speaking (adjective)	articulate (adjective)
capable of or involving speech or speaking	expressing yourself easily or characterized by clear expressive language
capable of speech	consisting of segments held together by joints

speaking (verb)	articulate (verb)
	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