17. can/should i ask you a question? 18. will/shall we go out for lunch today? 19. you must/shouldn’t stay at home if you are ill. 20. tommy can’t/couldn’t tell the time when he was a baby. 21. my book can’t/mustn’t be in the house. i’ve looked everything. 22. you haven’t/needn’t clean the windows. i’ve already done them. 23. sam left late for the airport this morning. he should/could have missed his flight.
Shall we go for lunch tonight?
You must stay at home if you are ill.
Tommy couldn't tell the time when he was a baby.
My book can't be in the house. I've looked everything.
You haven't clean the window . I have already done them
He could have missed his flight.