He's shaving at eight o'clock.句中有动词shaving了 为什么还要用be动词is

问题描述:

He's shaving at eight o'clock.句中有动词shaving了 为什么还要用be动词is
去掉is.改为He shaving at eight o'clock.

不可以,现在进行时由be doing构成,be 是助动词,帮助现在分词doing 一起构成时态.那要是一般现在时的动词原形呢, 也要用be(助动词)吗?比如 He is shaves at eight o'clock.不需要。一般现在时,在肯定句中不需要助动词He shaves at eight o'clock. 就可以了变否定句需要助动词帮忙