Proto-Polynesian had five simple vowels, /a/ /e/ /i/ /o/ /u/, with no length distinction. In a number of daughter languages, successive sequences of vowels came together to produce long vowels and diphthongs, and in some languages these sounds later became phonemic.
The following is a table of some sample vocabulary as it is represented orthographically in various languages. All instances of <ʻ> represent a glottal stop, IPA /ʔ/. All instances of <ng> and Samoan <g> represent the single phoneme /ŋ/. The letters <r> in all cases represents voiced alveolar tap /ɾ/, not /r/.
^Kirch, Patrick Vinton; Roger Green (2001). Hawaiki, Ancestral Polynesia: An Essay in Historical Anthropology. Cambridge University Press. pp. 99–119. ISBN978-0-521-78309-5.
^Rolle, Nicholas (2009). "The Phonetic Nature of Niuean Vowel Length". Toronto Working Papers in Linguistics (TWPL): 31.
^Hockett, C.K. (May 1976), "The Reconstruction of Proto Central Pacific", Anthropological Linguistics18 (5): 187–235
^Archaic: the modern Tahitian word for two is piti, due to the practice of pi'i among Tahitians, a form of linguistic taboo. However the cognate remains in the second-person dual pronounʻōrua, roughly translated you two.