Comparative Yupik and Inuit.

This site points out there may be an additional branch of languages here, the Sirenikski of Siberia (who are nearly extinct). However, their language is usually classified with the Yupik.

The Yupik and the Inuit are very similar, but differ in some important regards. The Yupik have an extra vowel sound: the "shwa", which sounds similar to the "e" in the word, "roses". Common vowels are: a, i, u.

Yupik tongues are also rhythmic, with patterns of stressed and unstressed syllables. Voiceless fricatives are more common in Yupik, and Inuit is marked by consonant assimilation.

Both branches of languages have similar grammatical rules.

Inuit is the same language across the continent, although dialects from one side to the other will appear very dissimilar to speakers of geographically distant dialects.

Yupik has four main languages, including some dialect variances: "Alutiiq (Sugpiaq) on much of the coast of the Gulf of Alaska, Central Yupik of Bristol Bay and the Yukon-Kuskokwim delta, Naukanski (spoken by 70 people out of 400 whose ancestors spoke the language) in the East Cape area on the Chukotkan Siberian shore of Bering Strait, and Siberian Yupik on St. Lawrence Island and the facing shore of Chukotka in Siberia. Linguistically, the progression of change goes from Alutiiq to Central Yupik up north and over to Naukanski Yupik and then down to Siberian Yupik"