钟头

wǒ děng le liǎ zhōng tóu le

我等了俩钟头了。

I've been waiting for two hours.

wǒ yī gè zhōng tóu qián huí de

我一个钟头前回的。

I got back an hour ago.

wǒ men wǔ fàn shí xiū xi le bàn gè zhōng tóu

我们午饭时休息了半个钟头。

We took a half hour lunch break.

sì gè bàn zhōng tóu

四个半钟头

four and a half hours

lián zhe gōng zuò jǐ gè zhōng tóu

连着工作几个钟头

work for hours at a stretch