Which major language group is found on all six inhabited continents?

The major language group found on all six inhabited continents is Indo-European.

Here's why:

* Europe: Indo-European languages are dominant across Europe, including Romance, Germanic, Slavic, and Celtic languages.

* Asia: Indo-European languages are prevalent in South Asia (Hindi, Urdu, Bengali), Central Asia (Persian, Pashto), and parts of Western Asia (Armenian, Kurdish).

* Africa: Indo-European languages are spoken in Southern Africa (Afrikaans) and parts of North Africa (Arabic, Berber).

* North America: English, a Germanic Indo-European language, is the dominant language in the United States and Canada.

* South America: Spanish and Portuguese, Romance Indo-European languages, are widely spoken in South America.

* Australia: English, a Germanic Indo-European language, is the official language of Australia.

While other language families are spoken on multiple continents, Indo-European is the only one with such widespread geographical distribution.