Ex4.
1. is swimming
2. is not going
3. is moving
4. are talking
5. are trying
6. are watching
ex5
1-question word
2. be
3. subject
4. -ing form
5. -?
ex6.
1. Is your mum working? Yes, she is. ( No, she is not ).
2. Are you writing in English? Yes, I am. ( No, I am not )
3. Are your classmates studying grammar? Yes, they are. (No, they are not )
4. Are your friends playing football? No, they are not. (Yes, they are )
5. Are you listening to music? Yes, I am. (No, I'm not ).
6. Is your teacher writing? Yes, she is. (No, she is not )