1. What is your hobby?

→ What hobby do you like?

2. We all find painting interesting because it’s a creative activity.

→ We all think painting is interesting because it's a creative activity.

3. His hobby is collecting toy cars.

→ He collects toy cars as his hobby.

4. It isn’t necessary to finish the work today.

→ You don’t need to finish the work today.

5. When did you start your hobby?

→ How long have you started your hobby?