他是我的汉语老师。

Tā shì wǒde Hànyǔ lǎoshī.

He is my Chinese teacher.

你懂说汉语吗?

Nǐ dǒng shuō Hànyǔ ma?

Do you speak Mandarin?

我现在在中国学汉语。

Wǒ xiànzài zài Zhōngguó xué Hànyǔ.

I am currently in China studying Mandarin.