1个半小时用英语表达为：one and a half hours；

hours：

n.小时;约一小时的时间;(工作、办公等的)固定时间

hour的复数

One and a half hours are allowed for the exam.

考试时间为一个半小时。

He spoke for one and a half hours and barely paused for breath.

他几乎一口气没停地说了一个半小时。

One and a half hours is enough for me.

对我来说一个半小时足够了。

After about one and a half hours, they finished the work.

大约一个半小时以后，他们做完了工作。

I kept swimming for about one and a half hours.

我一直游了一个半小时。