Study some information about negative sentences and questions with 'must'.
Щоб побудувати заперечне речення з must, необхідно дотримуватися наступного порядку слів:
subject \(+\) must \(+\) not \(+\) Verb in the \(1\)st form (without 'to') \(+\) other parts of the sentence.
Також можна вживати скорочену заперечну форму:
must not \(=\) mustn't.
You mustn't (must not) take this mobile phone. It's not yours.
Щоб побудувати загальне та спеціальне питання, вживайте наступні конструкції:
General question
Must \(+\) subject \(+\) Verb in the \(1\)st form (without 'to') \(+\) other parts of the sentence?
Special question
Question word (when, how, what....) \(+\) must \(+\) subject \(+\) Verb in the \(1\)st form (without 'to') \(+\) other parts of the sentence?
Must I help in the garden?
What must she read now?
Джерела:
https://www.entrepreneur.com/article/275880
https://www.rd.com/advice/parenting/get-your-kids-off-their-phone/