You must finish your homework before you can go out to play.I should probably start studying for the exam next week.You may have to work overtime to meet the deadline.We must follow the rules and regulations of the company.You should always be respectful to your elders.I may need to call in sick tomorrow if I don't feel better.We have to be at the airport by 6 AM for our flight.You should ask for permission before using someone else's belongings.I must remember to buy groceries on my way home from work.You may have to finish the project on your own if your partner is absent.