building vs roof

building and roof both are nouns.

Word	Noun	Adjective	Verb	Adverb
building	Yes	No	No	No
roof	Yes	No	Yes	No

building (noun)	roof (noun)
the act of constructing something	a protective covering that covers or forms the top of a building
the commercial activity involved in repairing old structures or constructing new ones	protective covering on top of a motor vehicle
a structure that has a roof and walls and stands more or less permanently in one place	an upper limit on what is allowed
the occupants of a building	the inner top surface of a covered area or hollow space

building (verb)	roof (verb)
	provide a building with a roof; cover a building with a roof