Trả lời: 1. infinitives without to2. infinitives without to3. infinitives with to
Trả lời: 1. Did you use to commute to school by the school shuttle bus?2. Do you have to work overtime on Sundays?3. Do you want to take part in the Young Musician of the Year contest?
Trả lời: 1. has to2. fly3. go4. to swim5. ought to6. don't need
Trả lời: infinitives without to: begin, start, decide, refuse, ...infinitives with to: might, would, could, don't, didn't, ...
Trả lời: 1. a lot of / lots of2. any3. Some4. any