Too funny! "here mom, aren't you proud? Look how well I'm learning, and check out this yummy I'm presenting!"
Ya, I think my tone does more than the command for the most part, but I do try to diferentiate the commands so even if they are in the same tone, I get a slightly different reaction. I practice these a lot when we're playing fetch or on our walks so they get reinforced on a pretty regular basis.
That being said, Nina's been taught:
Leave It: generally referencing something she wants to look at/chase/worry about - so another dog, a cat, whatever. For us it means your focus needs to be elsewhere.
Oust: If you're chasing it, or just grabbed it, stop NOW. We practice this with her toys, I haven't had to use it outside of play time yet, but if a cat ever is dumb enough to go into our back yard I will probably have to use it.
Drop It: If it's in your mouth, it should be out of it.
Bring it here: self explanatory.