记住：''half the time“不是”一半的时间''

​ 01 half the time

一半的时间 ×

时常发生 √

Half the time, I don't have any idea what he's talking about.
​02 in half

在一半 ×

弄成两半 √

He ripped the paper in half.他把纸撕成两半。(in halves也可以）
​

03 by half

用一半 ×

原来数量的一半 √

The population has increased by half over the past 20 years. 在过去的20年人口增长了一半。