Comment inviter une personne:
...? = Do you want to...?
...? = Can you...?
= with me
= with you
= Do you want to play tennis?
= Can you speak to my friend (m)?
= Do you want to have dinner with me?

Comment accepter une invitation:
= Yes, of course.
= Yes, thanks.
= Yes, all right, okay.
= Yes, I'd love to.
= Yes, of course, I'd love to.
= I'd love to eat dinner with you.

Comment décliner une invitation:
= I'm sorry.
= I can't.
... = I have to/I must...
= I'm sorry, but I can't.
= I have to study.
= I have to play soccer.
= I have to eat dinner with my family.
= I can't eat dinner with you.
= I can't swim.