Fill in: will, won't or shall. Fred: I hope you 1) will be able to come to my party this weekend, Emma.

Emma: Of course I 2) ... Fred. But I'm afraid Sue 3) ... be able to.

Fred: Oh dear! I know a certain boy who 4) ... be very disappointed about that!

Emma: 5) ... I phone her and try to persuade her to come? It probably 6) ... do any good, but it's worth a try.

Fred: Yes, 7) ... you do that? Gary 8) ... enjoy himself if she doesn't come.

Fred: I hope you will be able to come to my party this weekend, Emma.

Emma: Of course I will, Fred. But I'm afraid Sue won't be able to.

Fred: Oh dear! I know a certain boy who will be very disappointed about that!

Emma: Shall I phone her and try to persuade her to come? It probably won't do any good, but it's worth a try.

Fred: Yes, shall you do that? Gary will enjoy himself if she doesn't come.

Explanation:

1) will - In this sentence, Fred expresses a hope for Emma's future action (coming to the party) and uses the modal verb "will" to indicate a future possibility.

2) will - Emma responds to Fred's invitation and agrees to come to the party, indicating her future willingness using the modal verb "will".

3) won't - Emma explains that Sue won't be able to come to the party, indicating a negative future possibility using the modal verb "won't".

4) will - Fred expresses that a certain boy (probably himself) will feel disappointed, using the modal verb "will" to indicate a future emotional state.

5) Shall - Emma suggests the idea of calling Sue to persuade her to come to the party, using the modal verb "shall" to suggest a future action.

6) won't - Emma anticipates that calling Sue probably won't have a positive effect, indicating a negative future possibility using the modal verb "won't".

7) Shall - Fred agrees with Emma's suggestion and asks her to proceed with the plan, using the modal verb "shall" to indicate a future action.

8) will - Fred expresses that Gary will enjoy himself if Sue doesn't come to the party, indicating a future possibility using the modal verb "will".