Infinitive with to / without to or Gerund:
1. I would love TO SEE (see) you tonight.
2. I am glad TO MEET (meet) you here.
3. He is too old TO DRIVE (drive).
4. She is clever enough TO UNDERSTAND (understand) it.
5. We must LEAVE (leave) soon.
6. He started TO DO // DOING (do) his homework at 5:00 pm. = оба варианта возможны после глагола start, без изменения смысла)))
7. My dad lets me USE (use) his computer.
8. My sister promised TO LOOK AFTER (look after) them properly.
9. She went SKIING (ski) last Sunday.
10. SWIMMING (Swim) keeps you fit.
11. You must BE (be) worried about the race.
12. He left without TAKING (take) his coat.