他在国外工作了三年以后才回国。

Tā zài guówài gōngzuò le sān nián yǐhòu cái huíguó.

He only returned to his country after working abroad for three years.

他在国外工作。

Tā zài guówài gōngzuò.

He works abroad.

很多人喜欢去国外旅游。

Hěn duō rén xǐhuān qù guówài lǚyóu.

Many people like to travel abroad.