为了让孩子开心，爸爸给他买了一个玩具。

Wèile ràng háizi kāixīn, bàba gěi tā mǎi le yí gè wánjù.

To make the child happy, the father bought him a toy.

为了考试，他每天学习到很晚。

Wèile kǎoshì, tā měitiān xuéxí dào hěn wǎn.

In order to prepare for the exam, he studies until very late every day.

我们为了省钱，一起做饭，不去外面吃。

Wǒmen wèile shěngqián, yìqǐ zuòfàn, bù qù wàimiàn chī.

In order to save money, we cook together instead of eating out.