Use the infinitive with or without to. 1. I had better

Use the infinitive with or without to. 1. I had better (not/smoke). 2. I forgot (do) my homework yesterday. 3. I heard them (come) late at night. 4. You won39;t be able (go) to the party if we dont find the keys. 5. I couldn39;t go to to the cinema because I had (look) after my little sister. 6. Susan would rather (study) for her exam tomorrow. 7. Can you tell me how (get) to the bus stop?