Mine and my brother's old school"

[SoupDragon]

The above is from DSs homework. It's not right is it? It doesn't sound it but I can't work out what it should be as they all sound wrong now...

My and my brother's old school
My brother's and my old school

Aargh! Which is right?? I think "my and my brother's" but I'm no longer sure.

I would go with My and my brother's, because if you take away 'and my brother's' it still makes sense. Mine old school isn't right.

Although my first instinct was to say Me and my brother's, and that's how I would say it (informal, and wrong!)

Thsnks :) They all sound wrong to me now.

Turns out he's handed it in already, complete with crappy grammar. Gah!

I think it helps in these situations to take parts out and see if it still makes sense. So you wouldn't say "Mine old school"- well not unless you were in some cod historical comedy- so "My" is right, with the "and my brother's" added in. It's the downside of the fact that English is too snazzy these days to say "The school of my brother and me".

my brother's and my