Question

I have trouble using those three expressions when someone is proposing plans.

For instance : if someone ask me : " do you wanna go to a bar ?

Can i use the 3 expressions in this situation ? : I'm up for it;  i'm down, I'm in.

Thanks in advance.

Answer 1

You can absolutely use all three.  Personally I think "I'm up for it" sounds a bit preppy or overly eager.  I'm in and I'm down are very casual.  I'm down= the least formal, slang term.