Hải ____ his homework, so he can watch TV now.
- A. has finished(correct answer)
- B. have finished
- C. has finish
- D. finishing
Why: The result is now: Hải can watch TV. Hải = he, so has + finished.
A212 questions · Elementary · Tenses and Time
Have you finished, or did you finish? Practise have and has, past participles like gone, eaten and done, negatives, questions, been or gone, and when to switch to the past simple. Answers and short explanations included.

1.Hải ____ his homework, so he can watch TV now.
Why: The result is now: Hải can watch TV. Hải = he, so has + finished.
2.We ____ to Nha Trang in 2019.
Why: In 2019 is a finished time. Use the past simple: went.
3.____ your cousins arrived?
Why: Your cousins = they, so Have.
How to form the present perfect with have / has + past participle, negatives and questions, when it replaces the past simple, and been vs. gone.
Use the present perfect for something that started in the past and is still true: for + a length of time, since + a starting point, How long…? and It's … since.