(Lower Fly) Ipiko (Inland Gulf) Languages within the Southern New Guinea linguistic area generally share these typological features. lack of tone (except Kuni-Boazi, possibly Marind, and some Kiwai dialects) complex verb morphology limited or no gender (except for the four-way gender system in Anim languages, and the masculine vs. feminine contrast on undergoer-prefixes in the Tonda languages and some Oriomo languages) lack of verb chaining or switch-reference single-word verbs form an open class Pronouns The pronouns Ross reconstructs for the three families he keeps together are suggestively similar, but it has not been possible to reconstruct common forms: Proto-Yam (Proto–Morehead – Upper Maro) {| class=wikitable |- | I/we||*ni |- | you||*bu |- | s/he/they||*be |} Proto-Pahoturi {| class=wikitable |- | I||*ŋa-na||we||? |- | thou||*ba or *be||you||*-bi |- | s/he||*bo||they||? |} Proto–Bulaka River {| class=wikitable |- | I||*ŋöl||we||*ŋag |- | thou||*ob||you||*el |- | s/he||*ib||they||*im |} Lexical comparison The lexical data below is from the Trans-New Guinea database and Usher (2020) (for Proto-Kiwai), unless noted otherwise. Neighboring languages not traditionally classified within Trans-Fly–Bulaka River are also included for comparison. See also Trans-Fly languages References External links South-Central Papuan languages database at TransNewGuinea.org Bulaka River on newguineaworld Proposed language families Papuan languages