I had to run like mad to catch the bus.

为了赶上公共汽车，我不得不拼命跑。

I've gotta catch the bus.

我要去赶公共汽车了。

He says he must catch the bus.

他讲他必须遇上那辆大众汽车。

Because I didn't catch the bus.

因为我没有赶上公共汽车。

He didn't run to catch the bus.

他跑得不够快，没能赶上公共汽车。