2 'Does Harry has to get up early?' 'No, he doesn't.'
3 we have get to school before 8.30 a.m.
4 Jason and Sarah has to wear a uniform.
5 'Do you have to stay at school for lunch?' 'Yes, I have.
6 We doesn't have to do homework at the weekend.​

1. I have to study French .

2. 'Does Harry have to get up early?' 'No, he doesn't.'  [Does + He, she, it + ; базовая форма глагола без окончания!]

3. We have to get to school before 8.30 a.m. [Не забываем ставить 'to']

4. Jason and Sarah have to wear a uniform.  [Jason and Sarah - they (они)]

5. 'Do you have to stay at school for lunch?' 'Yes, I do' [В кратких ответах ставим вс глагол - здесь это do]

6. We don't have to do homework at the weekend.​ [I, you, we, they + don't + ]