A: Hi, Amy, can you come to my birthday party ? 
B: Oh, your birthday party ! When is it ?
A: It’s on Saturday, August 15 at eight p.m.
B: Oh, let me see! Sure, I’d love to. But I’m having a computer lesson in the afternoon. After class, I have to see my grandma at seven. Because she is ill. Can I go a little later?
A: Of course!
B: Thank you for your invitation.