помогите пожалуйстаПереведите предложения, обращая внимание на необыкновенности использования

Помогите пожалуйста
Переведите предложения, обращая внимание на особенности использования модальных глаголов.

1. I must say, you are making а serious mistake.
2. It stopped raining, and mother told us that we might go out.
3. You must listen to the tape recording of this text several times.
4. They are to visit their grandmother at 5 oclock.
5. I am sorry I couldn't соmе yesterday, I had to work late.