it is high time that有的在后面加（should）+动词原形,有的在后面加虚拟语气如It is high time that such practices were ended.什么时候用前者,什么时候用后者?最好系统地把it is high time这个句型的用法说一

it is high time that有的在后面加（should）+动词原形,有的在后面加虚拟语气如It is high time that such practices were ended.什么时候用前者,什么时候用后者?最好系统地把it is high time这个句型的用法说一
it is high time that
有的在后面加（should）+动词原形,有的在后面加虚拟语气如It is high time that such practices were ended.
什么时候用前者,什么时候用后者?最好系统地把it is high time这个句型的用法说一遍,小生感激不尽!
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it is high time that有的在后面加（should）+动词原形,有的在后面加虚拟语气如It is high time that such practices were ended.什么时候用前者,什么时候用后者?最好系统地把it is high time这个句型的用法说一
就两种用法.
It is (high) time that后面的从句谓语动词
要么用过去式或者用should+动词原形,但should不可省略.
如：
It is high time that the children went to school.
It is high time that the children should go to school.

其实就是楼主说的这两种用法。
It is (high)(这个可以省略）time that sb. should do sth.
sb. did sth
就是两种用法，意思都一样：是（到了）做……的时间了。