现在进行时变否定句怎么变？详解如下：
1.肯定变否定，be动词后加个not
am → am not  (无缩写)
is  → is not = isn't
are →  are not = aren't 

【例子】
I am running. →
I am not running.
我不在跑步。

He is running. →
He isn't running.
他不在跑步。

They are running. →
They aren't running.
他们不在跑步。

The boy is watching TV. →
The boy isn't watching TV.
那个男孩子没有在看电视。

现在进行时变否定句的介绍就到这里。相关知识：
现在进行时变一般疑问句