What language family has spread to every continent?

The language family that has spread to every continent is Indo-European.

Here's why:

* Historical Expansion: Indo-European languages originated in the Pontic-Caspian Steppe, and their speakers migrated across Europe and Asia, eventually reaching the Americas and Australia.

* Colonialism: European powers, speaking Indo-European languages, colonized vast swathes of the globe, leading to the spread of these languages through administration, education, and trade.

* Global Influence: English, a major Indo-European language, has become the dominant language of international communication, science, and business, further accelerating its global reach.

While other language families like Sino-Tibetan and Afro-Asiatic have substantial numbers of speakers and geographical spread, they haven't reached every continent.