English for Today by Ganiu Abisoye Bamgbose (Dr GAB)
TO SLEEP or TO SLEEP OFF?
She ~slept off~ before I returned home (nonstandard).
She *slept* before I returned home (standard).
Note that “doze off” and “nod off” are synonyms for “sleep” but “sleep off” means something else.
If you sleep off the effects of too much travelling, drink, or food, you recover from it by sleeping:
He may have to *sleep off* his hangover (standard).
GAB
No comment