Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
Area where Dupaningan Agta is spoken according to Ethnologue
Dupaningan Agta (Dupaninan Agta), or Eastern Cagayan Agta, is a language spoken by a semi-nomadic hunter-gatherer Negrito people of Cagayan and Isabela provinces in northern Luzon, Philippines. Its Yaga dialect is only partially intelligible.
Geographic distribution and dialects
Robinson (2008) reports Dupaningan Agta to be spoken by a total of about 1,400 people in about 35 scattered communities, each with 1-70 households.
Palaui Island - Speakers do not consider themselves to be Dupaningan, but the language is very similar to that of the other Dupaningans.
Ethnologue reports Yaga, Tanglagan, Santa Ana-Gonzaga, Barongagunay, Palaui Island, Camonayan, Valley Cove, Bolos Point, Peñablanca, Roso (Southeast Cagayan), Santa Margarita as dialects of Dupaningan Agta.
Phonology
Consonants
Labial
Alveolar
Velar
Glottal
Stop
p b
t d
k g
(ʔ)
Nasal
m
n
ŋ
Trill/Tap
r~ɾ
Lateral
l
Fricative
s
h
Glide
w
j
Where symbols appear in pairs, the one to the right is voiced.
Vowels
Front
Central
Back
High
i
u
Mid
e
o
Low
a
/a, e/ have lax allophones of .
References
^ Robinson, Laura C. (2008). Dupaningan Agta: Grammar, vocabulary, and texts (Thesis). University of Hawaii at Manoa. hdl:10125/20681.
^ http://www.ethnologue.com/language/duo Lewis, M. Paul, Gary F. Simons, and Charles D. Fennig (eds.), 2013. Ethnologue: Languages of the World, Seventeenth edition. Dallas, Texas: SIL International.
Robinson, Laura C. (2011). Dupaningan Agta: grammar, vocabulary, and texts. Canberra: Pacific Linguistics. ISBN978-0-858-83646-4., slightly revised from Robinson's 2008 thesis