流利地

He had the assurance to claim that he could speak ten foreign languages perfectly.

他竟狂妄地宣称他利地讲十种外语。

He is fluent in five languages.

他利地说五种语。

You may be able to read French well, but speaking it fluently is a different kettle of fish entirely.

也许很利地看法语，但要利地说法语就是另一码事了。

It is quite unthinkable that a child like him can speak a foreign language so fluently.

像他这样的孩子居利地说一种外语, 真是令人难以置信。