Answer:1. You must finish your homework before going home.2. She must be at home; I saw her car.3. We should finish our homework before going home.4. He could run faster when he was younger.5. They might bring their jackets; it looks like rain.6. You should be more careful when crossing the street.7. I would help you with your assignment.8. You should try the new restaurant.9. She must call her parents to tell them she's running late.10. He must have left his keys at home.And here are the corrected sentences with modal verbs:1. You must finish your homework...2. She must be at home...3. We should finish our homework...4. He could run faster...5. They might bring their jackets...6. You should be more careful...7. I would help you...8. You should try the new restaurant...9. She must call her parents...10. He must have left his keys...Modal verb usage:Must: necessity/obligationShould: advice/recommendationCould: past ability/possibilityMight: possibility/uncertaintyWould: conditional/hypothetical situations