In Canada and the United States,people enjoy entertaining (请客) at home.They often invite friends

In Canada and the United States,people enjoy entertaining (请客) at home.They often invite friends
over for a meal,a party or just for coffee and conversation.
Here are the kinds of things people say when they invite someone to their homes:
"Would you like to come over for dinner this Saturday night?" "Hey,we're having a party on Friday.
Can you come?"
To reply to an invitation,either say thank you and accept,or say you're sorry and give an excuse."Thanks,
Fd love to.What time would you like me to come?" or "Oh,sorry.I've tickets for a movie."
Sometimes,however,people use expressions that sound like invitations but which are not real invitations.
For example; "Please come over for a drink sometime." "Why not get together for a party sometime?" "Why
don't you come over and see us sometime soon?"
They are really just polite ways of ending a conversation.They are not real invitations because they don't
mention a certain time or date.They just show that the person is trying to be friendly.To reply to expressions
like these,people just say "Sure,that would be great!" or "OK.Yes,thanks."
So next time when you hear what sounds like an invitation,listen carefully.Is it a real invitation or is the
person just being friendly?
Why do people say this if they don't really want to invite friends to come?
Write an answer to accept an invitation.