[1] However, according to Dryer (2022), based on a preliminary quantitative analysis of data from the ASJP database, South Bird's Head languages are likely to be a subgroup of Trans–New Guinea.

[5] Usher classifies the South Bird's Head languages as part of a wider Berau Gulf branch of Trans–New Guinea.

Below are cognates in Nuclear South Bird's Head languages (Arandai, Kokoda, Kemberano, Kaburi, Kais, Puragi) demonstrating their relatedness, as listed by Holton & Klamer (2018):[5] South Bird's Head basic vocabulary quoted by Holton & Klamer (2018)[5] from de Vries (2004), showing diverse non-cognate vocabulary across different language groups:[6] Except for the outlier languages Konda and Yahadian, all South Bird's Head languages have nouns classified according to masculine and feminine genders, which are determined with final vowel quality.

[5] West Bird's Head languages also mark nouns for gender.

Unlike many other languages of the Bird's Head Peninsula which display SVO word order (such as Abun, Mpur, Maibrat, West Bird's Head, and others), the South Bird's Head languages have SOV word order.