1. Hoa goes shopping in her free time.
=> What does Hoa do in her free time ?
2. Mai goes fishing twice a week.
=> How often does Mai go fishing ?
Or : How many times a week does Mai go fishing ?
3. Ba goes camping once a month.
=> How often does Ba go camping ?
Or : How many times a month does Ba go camping ?
4. Minh goes camping in the country.
=> Where does Minh go camping ?
5. Hoa and Lan go swimming once a week.
=> How often do Hoa and Lan go swimming ?
Or : How many times a week do Hoa and Lan go swimming ?
6. They do their homework every day.
=> How often do they do their homework ?
7. They play badminton after school.
=> When do they play badminton ?
8. They go to the library three times a week.
=> How often do they go to the library ?
Or : How many times a week do they go to the library ?