一阵子

wǒ yǐ jīng tīng shuō yī zhèn zi le

我已经听说一阵子了。

I've known it for a while.

guò yī zhèn zi nǐ huì xí guàn de

过一阵子你会习惯的。

You'll get used to it after a while.

dāng yǎn yuán yǐ qián tā chàng guò yī zhèn zi gē

当演员以前她唱过一阵子歌。

She had a spell as a singer before becoming an actress.