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!