Когда писать aren039;t you,а когда don039;t you?Не послушал тему, теснее 2

Когда писать aren't you,а когда don't you?Не послушал тему, теснее 2 за домашку получил. Растолкуйте пж.
Решите это(очень нужно):
20.
1) His name's George, ISN'T IT (образец)
2)You live in Bristol,.......
3) Ted is from Wales,.....
4)You're late,....................
You start school at nine o'clock every day,........ .
21
1) You're from London, aren't you?-No I'm not.I'm from Liverpool.
2)....... playing tennis, don't touch?-Yes, I do.I pay every day.
3)...... thirteen years old, aren't you?-Yes, I am.
4)...... In the flat, don't you?-No, I don't.I love in a house.
5)......
6)...... The violin, don't you?-Yes, I do. I okay in an orchestra.
7)...... school at nine o'clock,don't you?-No, I don't.I start at eight o'clock.