Ответ:

1. *Здесь скорее всего опечатка, не "I", а "It"* > is, are

2. are

3. is

4. is

5. is swimming

6. is coming

7. costs

8. is speaking

9. don't watch

10. don't understand

11. is singing

12. is, has been

13. are, have been

14. has visited

15. has been working

Buy - Bought - Bought

Catch - Caught - Caught

Come - Came - Come

Cost - Cost - Cost

Do - Did - Done

Drink - Drank - Drunk

Eat - Ate - Eaten

Break - Broke - Broken

Find - Found - Found  

Fall - Fell - Fallen

Give - Gave - Given

Have - Has - Had

Has Mr John just arrived from New York?

удачи!