Question

请问比较句型中than usual为什么不用than usually呢?例如Harvesting has begun e

Answer 1

因为这里usual修饰的是time, 相当于earlier than usual time,不能说usually time

类似的还有as usual, 例如 Harvesting has begun as usual (time).

至于usual后面指的是什么取决于上下文,as usual way/situation等,也是可以的.

用usually的情况例如,We left school earlier than we usually do. = earier than usual