I couldn't /can't come to the picnic tomorrow . I could /can swim when I was very young.
You must/have remember to put the milk back in the fridge.
If you are going out in the rain , you should/can take an umbrella.
Do you have to/ must tidy your room every week?
I don't know if I should/have to tell you the secret.
She must/has stay in tonight. Should/can I watch TV now ,please ?
I don't know you could/should speak French when you were little.
Maybe your dad must/ could drive us to the party.
Do you think I have/ should tell him.​

1. If you had brought me the book, I should have read it. 2. If he didn't ring me up, I woudn't come. 3. If he hadn't written to me, I shouldn't have answered him. 4. I wish I had a tie to match my suit. 5. The doctor suggested that she had a long rest in the Crimea. 6. If I had been you, I should have appologised to her. 7. You wouldn't have so many accidents if you drove slowly. 8. If he were in, he would answer the phone. 9. If you had passed your examination, we should have a celebtarion. 
10. What might happen if I pressed the button? 11. I should not have taken your umbrella if I had known that it was the only one you had. 12. If he knew it was dangerous he wouldn't come. 13. I shouldn't have gone there if I had been you. 14. He would have been the best pupil in the class if he had worked harder. 15. We would have stayed at home if we had known he was comung. 16. He might have understood everything if you had spoken not so fast. 

1)  Does the girl clean her room on sundays?

Does the girl clean her room on sundays or on mondays?

What does the girl usually do on  sundays?

When does the girl usually clean her room?

Why does the girl clean her room on sundays?

Which of the rooms does the girl usually clean on sundays?

The girl usually cleans her room, doesn't she?

Who usually cleans the room on sundays?

2) Who is eating the porridge now?

The dog is eating porridge now, isn’t it?

Is the dog eating the porridge now?

Is the dog eating the porridge or the soup now?

What is the dog eating?

Why is the dog eating porridge?

3) The boy has done this work, hasn’t he?

Has the boy done this work?

Why has the boy done his work?

Has the boy done this work or another work?

What has the boy done?

Who has done this work?