英语专家请进 急!关于be able to 的否定,课文是这样写的:sometimes you may work for
英语专家请进 急!
关于be able to 的否定,
课文是这样写的:sometimes you may work for many hours,but still not be able to write a good report.
请问be able to 可以直接加not否定的吗?那么,be able to 中的be 是什么动词?如果是be 动词,那么为什么不是be not able to 呢?
如果将he can't swim 变成be able to 的形式进行转换,那么是he is not able to swim,he not be able to swim还是he didn't be able to swim,或者全部都不是啊?