We had a group of children who were monolinguals.

一组是单语儿童。

Also, bilingual people tend to trip over tongue-twisters more than monolingual people.

此外，双语者比单语者更容易被绕口令绊倒。

Number four is to use a monolingual dictionary more than a bilingual dictionary.

第四，多使用单语词典而不是双语词典。

In my opinion, it doesn't really matter whether you use a monolingual or bilingual dictionary.

在我看来，你用英英字典或是英汉字典都不太有关系。

How are the strategies that bilingual children use to learn language different from monolingual children?

双语儿童学习语言的策略和单语儿童有何不同？

But bilinguals, there's evidence showing that they're not relying on mutual exclusivity as much as monolinguals.

然而，有证据显示双语儿童不像单语儿童一样依赖互斥性原则。

A study of monolingual and bilingual speakers suggests speaking two languages can help slow down the brain's decline with age.

一份针对单语言和双语言者的研究表明，说两种语言可以延缓大脑随着年龄的衰退。

The answer is " an American." Well, the actual answer would be someone who is " monolingual" (monolingual).

答案是“一个美国人” 。好吧，实际的答案应该是一个“只讲一种语言” （monolingual）的人。

If you speak only one language, you're called " monolingual, " since " mono-" means one.

如果你只说一种语言，你就被称为“单一语言”，因为“单一”意味着一种。

Can language diversity be preserved, or are we on a path to becoming a monolingual species?

语言多样性能否得以保留， 或者我们是否正走上成为单一语言物种的道路？