因为你很忙，没有时间和我看电影。

Yīnwèi nǐ hěn máng, méiyǒu shíjiān hé wǒ kàn diànyǐng.

Because you're busy; you don't have time to watch movies with me.

因为第一件比第二件贵。

Yīnwèi dìyī jiàn bǐ dì'èr jiàn guì.

Because the first one is more expensive than the second one.

我今天不能去，因为我生病了。

Wǒ jīntiān bù néng qù, yīnwèi wǒ shēngbìng le.

I can’t go today because I’m sick.