他的英文说得很流利。

Tā de Yīngwén shuō de hěn liúlì.

He speaks English fluently.

他说话很流利，但是写汉字还不太好。

Tā shuōhuà hěn liúlì, dànshì xiě Hànzì hái bù tài hǎo.

He speaks very fluently, but his Chinese characters are still not very good.

我能说流利的普通话。

Wǒ néng shuō liúlì de Pǔtōnghuà.

I can speak fluent Mandarin.