3点半英语可以说作"half past three"或者"three-thirty"。这些表达方式来源于英语中表示时间的方法。在英语中，我们通常会用"past"或"to"来表示时间点，因此"half past three"表示三点半，"three-thirty"也表示三点半。

例句：

The movie starts at half past three.

I usually go to bed at three-thirty.

Can you meet me at half past three?

I'll be ready by three-thirty.