学习外语要达到流利或精确的程度都是不容易的。

Neither fluency nor accuracy is easy to come by in learning a foreign language.

他法语流利得使人以为他是法国人。

He speaks French well enough to pass for a Frenchman.

玛丽雄心很大，竟想在四个月里学会用汉语流利地会话。

Mary is ambitious enough to aspire to conversational fluency in Chinese in four months.