The North Halmahera (NH) languages, spoken in the Maluku Islands, share some structural similarities with certain Papuan families in Melanesia, which was noted as far back as 1900.

[3]: 626  The South Bird’s Head and Timor–Alor–Pantar families, while included in older formulations of the proposal, are no longer thought of as part of West Papuan.

[3]: 625 The term "West Papuan" has also been used in an areal sense, encompassing most of the non-Austronesian languages of Halmahera and Bird's Head.

[5] The German linguist Wilhelm Schmidt first linked the West Bird's Head and North Halmahera languages in 1900.

[6] In 2005, Malcolm Ross made a tentative proposal, based on the forms of their pronouns, that the West Papuan languages form one of three branches of an extended West Papuan family that also includes the Yawa languages, and a newly proposed East Bird's Head – Sentani family as a third branch.

Timothy Usher, also somewhat tentatively, accepts Yawa and East Bird's Head, but not Sentani, as part of West Papuan itself, so the family can remain under that name.

Ross's West Papuan proper is distinguished from Yawa and EBH-Sentani in having forms like na or ni for the second-person singular ("thou") pronoun.

Large consonant inventories similar to that of Abun are also found in the North Halmahera languages, such as Tobelo, Tidore, and Sahu.