1. At this time tomorrow, John will be lying on the beach.
2. Peter will help you when he will finish his dinner.
3. Will you do the shopping for me, please?
4. Sarah will finish decorating the Christmas tree to midnight.
5. Where will you spend your holidays this summer?
6. I turned on the heating. It's cold here.
7. The film started at half past six.
8. Stop that noise or I will take your toy away.
9. Moira can type these reports as soon as she come back from her lunch break.
10. Perhaps the Jacksons will visit us tonight.
11. By the end of the year, Mrs Evans will have been teaching for thirty years.
В 12 предложении на мой взгляд все правильно. 4 предложение я бы тоже оставила как есть. В общем вот, но 100% уверенности у меня нет.