There is 2 things about this. You get an offline (Splitscreen) exp system. and an Online exp system. which means if you play online. you gain exp normally. However if you start a split screen you get a new exp and start back at level 0. You get exp on split screen. However it doesn't add to your online profile. So your online profile could be level 60 where your offline (Split screen) profile could be level 30. Hope you understand and hope this helps you.
You can only do split screen if the person you are playing with is with you.
on split screen, no, on live, yes
yes
you cant
You can not play split screen on multiplayer. It also left me confused
You can't
No, you may not play Split Screen!
Call of Duty: Modern Warfare 3 for Wii doesn't have split screen because the Wii doesn't have enough RAM to handle split screen.
no
No, you can play splitscreen spec ops and offline multiplayer though
no not possible
yes but i dont think it makes a differents you still get the same guns