Wrete a letter to a friend to thank him/her for an invitation to dinner.

Excuse me. I don't understnd what it is mean the word "WRETE", so I cannot help you. May by you mix up tnlish with some other language, as german, and it's mean Write?

In this case the question is very simple, but the text will be very short, for example:

Dear friend,
I'd like to thank you for you invitation, and I'll be very glad to accept it (?).
Suncerely yours forever,
Mawka