Tombonuwo (Tambonuo) is a Paitanic language spoken in the Pitas and Labuk-Sugut Districts of northwest Sabah.  Tombonuwo is apparently also the name
The phonemes /p, t, k, s, ʔ/ are voiceless. All other expressions are voiced.
/o/ is often pronounced as unrounded [ʌ].
/a/ is neutralized to [ʌ] in a pre-stressed syllable.
Sabahan languages are characterized by "focus" morphology, which marks a syntactic relationship between the predicate of a clause and the "focused" noun phrase of the clause
(see  Austronesian alignment).
Tombonuwo has four focus categories, conventionally labelled "actor", "patient", "referent" and "theme".
Focus is marked by affixation on the verb.
-um- / m(u)- Patient:
-on (Present tense) / -∅ (Past tense) Referent:
-an Theme: i-
Tense and aspect 
The only marked tense in Tombonuwo is past tense.
n- ( -in-) Stative:
ko- Non-volitional past tense:
n-o- Accomplishment: n-o-ko-
Near the speaker:
itu Far from the speaker:
iri Medium distance from the speaker: ono
^ a b
Tombonuo at (18th ed., 2015) Ethnologue
Hammarström, Harald; Forkel, Robert; Haspelmath, Martin, eds. (2017). "Tombonuo". . Jena, Germany: Max Planck Institute for the Science of Human History. Glottolog 3.0
King, Julie (1984). . The Paitanic language family Languages of Sabah: a survey report. Canberra: Australian National University. p. 146. ISBN . 0858832976
Lobel, Jason William (2013). Philippine and North Bornean languages: issues in description, subgrouping and reconstruction (PDF) (PHD dissertation). Manoa: University of Hawai'i. p. 370.
King, John Wayne (1993). Tombonuwo phonemics. Phonological descriptions of Sabah languages. Kota Kinabalu: Sabah Museum. pp. 97–106. ISBN . 9789839638059
Boutin, Michael (1988). Problems in analyzing focus in the languages of Sabah. Borneo language studies I: Sabah syntax papers. Dallas: SIL. p. 54. ISBN . 0883122146
^ a b c
King, John Wayne; Levinsohn, Stephen (1991). . Participant reference in Tombonuo Thematic continuity and development in the languages of Sabah. Canberra: Australian National University. p. 76. ISBN . 0-85883-406-5