speech vs speak

speech is a noun but speak is not a noun.

Word	Noun	Adjective	Verb	Adverb
speech	Yes	No	No	No
speak	No	No	Yes	No

speech (noun)	speak (noun)
the mental faculty or power of vocal communication
(language) communication by word of mouth
the act of delivering a formal spoken communication to an audience
words making up the dialogue of a play
a lengthy rebuke
the exchange of spoken words
your characteristic style or manner of expressing yourself orally
something spoken

speech (verb)	speak (verb)
	express in speech
	exchange thoughts; talk with
	use language
	give a speech to
	make a characteristic or natural sound