“我之前是在这里，”他说着用红色彩笔划出一条水平线，表示他中风时的语言熟练程度。

"I was here," he says, using a red marker to draw a horizontal line indicating his skill level when he had his stroke.

youdao

其中，约4亿的人以英语为母语，另外还有同样数目的人把英语作为第二语言熟练使用。

That includes around 400m who speak it as their mother tongue and about the same number who speak it fluently as their second language.

youdao

能用一种语言熟练写作的人不一定能在用另一种语言写作时表现出同样的能力，这与个人对该语言语法的熟悉程度无关。

The ability to write well in one language does not necessarily guarantee an equivalent competence in another language, irrespective of an individual's grammatical proficiency in that language.

youdao

How many of you know more than one language pretty fluently?

你们有多少人能熟练掌握不止一门语言

耶鲁公开课 - 心理学导论课程节选