I wrote "the staff drink tea" it was not accepted and was stated "the staff drinks tea" not sure why. Could anyone shed some light on this anomoly.
Yes, "staff" is one of those ones that might be done either way. "The staff drink" sounds more British to me, but that might be because I'm American and "the staff drinks" would be more common here.
[As an aside, I don't know if this sentence also accepts "personnel" as a translation for "personel," but if it does, that, too, would take the plural ("the personnel drink tea").]