Choose the right word(s) to complete the sentences. 1. I really must / don’t have to start studying now because I want to pass all my exams. 2. Do you have / Must you go to school on Saturdays? 3. Yesterday I have / had to go to the doctor because I wasn’t feeling well. 4. Fortunately, we mustn’t / don’t have to finish our school project today. 5. You know you don’t have to / mustn’t use your mobile phone in here. 6. Stephen has / must help his parents every weekend. 7. Does Lisa have / Must Lisa walk to school? 8. You have / must listen carefully and do what I say.

I really must start studying now because I want to pass all my exams.
Здесь говорится о личной необходимости: человек сам понимает, что ему необходимо начать заниматься.

Do you have to go to school on Saturdays?
Вопрос с have to спрашивает, есть ли правило или обязанность ходить в школу по субботам.

Yesterday I had to go to the doctor because I wasn’t feeling well.
Had to — прошедшая форма от have to, потому что речь идёт о вчерашнем дне.

Fortunately, we don’t have to finish our school project today.
Don’t have to означает, что делать это не обязательно. Проект можно закончить позже.

You know you mustn’t use your mobile phone in here.
Mustn’t означает строгий запрет: здесь нельзя пользоваться телефоном.

Stephen has to help his parents every weekend.
Has to используется с he/she/it и показывает регулярную обязанность.

Does Lisa have to walk to school?
После does используется начальная форма глагола: have, а не has.

You must listen carefully and do what I say.
Must выражает сильное требование или приказ.