be vs sit

be and sit both are verbs.

Word	Noun	Adjective	Verb	Adverb
be	No	No	Yes	No
sit	No	No	Yes	No

As verbs, sit is a hyponym of be; that is, sit is a word with a more specific, narrower meaning than be:

be (verb)	sit (verb)
spend or use time	serve in a specific professional capacity
work in a specific place, with a specific subject, or in a specific function	be in a position in which one's upper body is largely upright and supported by one's backside
have an existence, be extant	show to a seat; assign a seat for
have life, be alive	take a seat
form or compose	be in session
have the quality of being; (copula, used with an adjective or a predicate noun)	sit and travel on the back of animal, usually while controlling its motions
occupy a certain position or area; be somewhere	assume a posture as for artistic purposes
be identical to; be someone or something	work or act as a baby-sitter
be identical or equivalent to	be around, often idly or without specific purpose
represent, as of a character on stage	be located or situated somewhere
be priced at
to remain unmolested, undisturbed, or uninterrupted -- used only in infinitive form