あなたは喫煙をひかえるべきです。

you (referring to someone of equal or lower status); dear (what a wife calls a husband)

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

smoking

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

to be temperate in; to refrain; to abstain; to hold back; to restrain oneself from excessive ...; to make notes; to jot down (e.g. phone number); to be in preparation for; to be in waiting for; to be soon; to be in the offing; to be in a close relationship (e.g. as a backer, etc.)

shall; should; must

be; is