You may go out with your friends - You may do it alone
You must read this book. - You must do it now
We had to go. It's high time. - You have to do your homework or you won't go with us
Would you mind opening the window? - Would you like to go to the cinema with me
You were able to do it but you missed the chance. - You will be able to do it when we return
You should listen adults. - You should do it as your parents said to you