英语从句itisnecessarythathefulfillthetaskbytheendofnextweek请问这里为什么要用动词原型fulfill呢？

Question

英语从句
it is necessary that he fulfill the task by the end of next week
请问这里为什么要用动词原型fulfill呢？

Answer 1

1. it is necessary that he fulfill the
task by the end of next week到下个周末为止完成这个任务是必要的。这是主语从句在虚拟语气中的运用。

It
is necessary that +主语+（should）+动词原形。 Should可以省去。it is necessary that he
should fulfill the task by the end of next week 。句中的should省去了，所以就变成了主语he +动词原型fulfill了。

2. 类似的结构还有：It is necessary (important,
strange, natural) that +主语+（should）+动词原形

1) It’s natural that she should
do so. 她这样做是很自然的。

2) It’s important that we should
take good care of the patient. 我们照顾好病人是重要。