Will and (be) going to

Put the verb into the most suitable form. Sometimes there is more than one possibility A has decided to learn a language A: I've decided to try and learn a foreign language. B: Have you? Which language [blank_start]are you going to[blank_end] learn?

Continuation A: Spanish B: Are you doing a course? A: Yes, it starts next week. B: That's great. I'm sure [blank_start]you'll enjoy / you're going to enjoy[blank_end] it. A: I hope so. But I think [blank_start]it will be / it's going to be[blank_end] difficult.

A wants to know about B's holiday plans A: I hear you're going on holiday soon B: That's right We're going to Finland A: I hope you have a nice time. B: Thanks. I [blank_start]will[blank_end] send you a postcard and I [blank_start]will[blank_end] get in touch with you when I get back

A invites B to a party. A: I'm going to have a party next Saturday. Can you come? B: On Saturday? I'm not sure. Some friends of mine are coming to stay with me next week, but I think [blank_start]they'll[blank_end] have left by Saturday. But if they're still here, I [blank_start]will not[blank_end] be able to come to the party. A: OK. Well, tell me as soon as you know. B: Right. I [blank_start]will[blank_end] call you during the week.

We use (be) going to... to say what somebody has already decided to do.