Staff that was

If the collective noun (staff) is acting as a single unit, use the singular verb: “The staff is very efficient.” If the collective noun is meant to highlight the actions of discrete individuals who are all doing different things, use the plural verb: “The staff are working on many projects for the holiday party.”

(c&p from 'tinternet)

So 'was' is correct unless your sentence goes on to comment further on the actions of the staff.

(that should have been t'internet!)

I agree with ana, but to me it sounds odd.

So not "the staff were in school by nine" but "the staff WAS in school by nine" ..

I think:

(All members of) the staff were in school by nine, or

The (whole) staff was in school by nine.

But nanamaz in your first sentence the verb 'were' applies to the members, which is plural, not the staff, which is singular.
Agree with ana it depends on the context.

Thanks for the help with this. I think I understand ?

Would it not sound better to say "who" rather that "that" because you are talking about people not objects?

Is your computer set to UK English? My last book was copy edited and proof read initially by an American who really messed up the text by accepting all the grammar and spelling changes suggested by Microsoft Word!

I would have used "were". Was sounds completely wrong to me.

Apart from what is considered correct by grammar buffs I wonder how many people would actually say "was." So as long as your readers understand what you are saying. It just does not matter. It sounds very archaic.

Surely you would say 'the staff who were on duty'. As Lillie points out they are people, not objects. It would then be impossible unnatural to say 'the staff who was on duty', unless you were talking about one person, in which case you would say 'the member of staff who was on duty'.

Unless it was just one (the member of staff) I must say 'was' sounds quite wrong to me.

Would anyone say 'staff' when they mean just one person? I'd have thought most people would say 'staff member' or 'member of staff'.

It's always as well to remember that spelling and grammar checkers are not infallible, she said with feeling, having done an awful lot of checking and proof reading over the years.

I'm enjoying reading this, I was an army brat, I went to so many schools and not being the brightest star in the sky, English grammar passed me by. Unfortunately

I'd concur with the 'who'. It pains me to see 'that' being used in respect of people. It will pain me even more when someone comes along and tells me that it's correct usage because 'that's how it is used by lots of people'; people who have never been taught how to use it...