INVITATION (WRITTEN)

Invitation is a way to invite someone or more to go to a place or to do something.
Here are some expressions you can use to invite someone and accept invitation.
INVITING SOMEONE
 I would like to invite you to come to my house
 If you are not busy, please try to come to my office
 Will you come to my party on Saturday night?
 Shall we see the film?
ACCEPTING AN INVITATION
 Great! Let’s do it.
 Thank you. I’d like too.
 That’s a good idea.
 That would be very nice.
DECLINING AN INVITATION
 I’m really sorry about that.
 Sorry, I can’t. I have to do something
 I’d love to. But I can’t