possible diphthongs of the five basic vowels discussed above. There are eight falling pairs , , , , , , , and , eight rising pairs , , , , , , , and , and four level pairs , , , and . The terms rising, falling and level refer to the rise or fall of sonority of the diphthongs. Within Wuvulu, there are three vowel pairs that do not exist that are common in other languages. Eo, oe, and ae are three pairs that do not occur in Wuvulu. Previous research suggests that diphthongs are not phonemic in Wuvulu. Consonants There are several publications on Wuvulu-Aua phonology, but they disagree on the allophones of the phonemes , , and . Two publications, Blust 1996 and 2008, vary the number of consonant phonemes, reducing from 14 to 12. The third publication, Hafford 2012, further reduces the consonant phonemes to 10. Wuvulu-Aua contains four plosives, , , , and . There are three approximates , , and . There is one fricative which is usually voiceless however when placed between vowels it can become voiced. And finally, there are two nasals and . There are no consonant clusters within the language. There are only three consonants that contain possible allophones. has three allophones - , , and ; has three allophones - , , and ; and has three allophones - , , and . All allophones are environmentally conditioned. The fricatives and are sometimes voiced intervocalically. The voiceless fricative is sometimes voiced -> . In rapid speech the voiceless fricative is sometimes voiced -> . The use of is not conditioned by a phonological rule. Older generations of Wuvulu-Aua speakers still use the phone. The alveolar trilled is also regularly used by older generations and is understood by children. will generally be used, otherwise and are uttered in complementary distribution (Hafford, 2015, pg. 38). If is adjacent to a [+high] vowel, will become a voiced alveolar stop -> 'child'. Wuvulu has four plural pronouns. For each of the plural pronouns, can be deleted -> (Hafford, 2015, pg. 39). Conditioned variants and have been proposed by Blust 2008. This proposal is a correction from Blust 1996 which proposed that , , , and are all free variation phones. All dialects of Wuvulu-Aua claim that is not a phone as borrowed words from English replace with ʔ. Syllable structure The syllable