The oldest of these, as far as we know, was the Indo-European family of languages, which were beginning to be spoken clear back during the Stone Age.

据我们所知，其中最古老的语言是印欧语系。 远在石器时代人们就开始使用印欧语了。

youdao

For example, most of the languages of Europe are in one large family called Indo-European.

例如，欧洲的大多数语言属于同一种语系，叫做印欧语系。

youdao

To do so he looked at three well-studied parts of the linguistic family tree: the Bantu languages of Africa, the Indo-European group from Eurasia and the Austronesians of the Pacific.

ECONOMIST: Languages and species evolve in surprisingly similar ways