否定词后加单数还是复数

这要看具体情况.

如：

He  isn't a  student.

They  aren't  students.

1、与不可数或复数名词连用，用于否定句和疑问句，也用于if或whether之后

I didn't eat any meat.我一点儿肉也没吃。

Are there any stamps?有邮票吗

I've got hardly any money.

我几乎不名一文。

You can't go out without any shoes.

你不能不穿鞋就出门。

He forbids any talking in class.他严禁课堂上讲话。

She asked if we had any questions.她问我们有没有问题。

2、 与单数可数名词连用

Take any book you like.你喜欢哪本书就拿哪本。

Any colour will do.什么颜色都行。

Any teacher will tell you that students learn at different rates.

任何老师都知道学生学习有快有慢。