have to
01
必须, 不得不
used to indicate an obligation or to emphasize the necessity of something happening
Transitive
例子
I have to finish this report by the end of the day.
我必须在今天结束前完成这份报告。
We have to pay our bills before the due date to avoid late fees.
我们必须在到期日之前支付账单以避免滞纳金。
02
必须, 一定
to be certain about something happening or being true in a given situation
例子
There has to be a reason for the sudden change in behavior.
行为的突然变化一定有原因。
It has to be a mistake; I never received that email.
这一定是个错误；我从未收到过那封邮件。
