have to
01
必须, 不得不
used to indicate an obligation or to emphasize the necessity of something happening
Transitive
例子
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
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。
