我睡觉以前，我要吃晚饭。

Wǒ shuìjiào yǐqián, wǒ yào chī wǎnfàn.

Before I sleep, I need to eat dinner.

我以前在这家公司工作过。

Wǒ yǐqián zài zhè jiā gōngsī gōngzuò guò.

I worked at this company before.

这里是我以前住的地方。

Zhèlǐ shì wǒ yǐqián zhù de dìfang.

This is where I used to live.