Have got to 英国英语更常用，更日常口语，也有说 have got to 比 have to 语气更强一些。

She has got to study hard to pass the exam.
她必须努力学习才能通过考试。
这句也可以说
She has to study hard to pass the exam.

上节课的句子“你必须得交税。You have to pay tax. ”也可以说
You have got to pay tax.

Have to 和 have got to的语法变化规则是不一样的，像前面第907课讲 have 和 have got 的变化规则，have to 的 have 是实义动词，但 have got to 的 have 是助动词，变疑问句和否定句不需要助动词。

你必须得交税。
You have to pay tax.
You have got to pay tax.
—> 变疑问句
你必须得交税吗？
Do you have to pay tax?
Have you got to pay tax?
—> 变否定句
你不必交税。
You don't have to pay tax.
You haven't got to pay tax.

我们必须得脱鞋吗？
take off 脱（鞋，衣服等）
Do we have to take our shoes off?
Have we got to take our shoes off?

我们不必付食物的钱。/我们不必为食物买单。
We don't have to pay for the food.
We haven't got to pay for the food.