1. My favorite subject is Math.

=> What is your favorite subject?

2. I have ever watched cartoon “ Tom and Jerry” many times.

=>who have you ever watched cartoon with many times?

3. Lan often listen to music in her free time.

=>what does Lan do in her free time?

4. Lan played badminton with her mother yesterday.

=>what did Lan do with her mother yesterday ?

5. They often listen to music in my free time..

=>What do they  do  in  your  free time ? 
6. He has traveled to Nha Trang many times.
=>where has he traveled  to many  times ?