他刚到中国的时候一句中文也不会，现在流利多了。

Tā gāng dào Zhōngguó de shíhou yí jù Zhōngwén yě bú huì, xiànzài liúlì duō le.

When he first arrived in China, he couldn’t speak a word of Chinese; now he’s much more fluent.

天黑了，我们快回家吧。

Tiān hēi le, wǒmen kuài huíjiā ba.

It’s getting dark; let’s go home.

太晚了，我得回家了。

Tài wǎn le, wǒ děi huíjiā le.

It’s too late; I have to go home.