Dưới đây là dạng đúng của từ trong ngoặc:

1. You (be) **have been** to Phong Nha before?
2. Would you mind (not use) **not using** the office phone?
3. Now they (play) **are playing** happily in the school yard.
4. They (not come) **did not come** to Maryam's farewell party last night.
5. A new hospital (build) **will be built** in my neighborhood next month.