"他很闲"可以用英文表示为"He is very idle."或"He has a lot of free time."

"Idle"这个词的意思是"懒惰的，不活跃的"，"free time"意思是"空闲时间"。

下面是一些使用"idle"的例句：

He spends most of his days being idle. 他的大部分时间都很闲。
The idle workers were not productive. 这些闲着的工人没有生产力。
The idle machine was not being used. 这台闲置的机器没有被使用。

下面是一些使用"free time"的例句：

I pke to spend my free time reading. 我喜欢在空闲时间看书。
She uses her free time to volunteer at a local shelter. 她在空闲时间去当地的避难所做志愿者。
He has a lot of free time because he retired early. 他有很多空闲时间，因为他早早就退休了。