Phonology
Proto-Austronesian is reconstructed by constructing sets of correspondences among consonants in the various Austronesian languages, according to the comparative method. Although in theory the result should be unambiguous, in practice given the large number of languages there are numerous disagreements, with various scholars differing significantly on the number and nature of the phonemes in Proto-Austronesian. In the past, some disagreements concerned whether certain correspondence sets were real or represent sporadic developments in particular languages. For the currently remaining disagreements, however, scholars generally accept the validity of the correspondence sets but disagree on the extent to which the distinctions in these sets can be projected back to proto-Austronesian or represent innovations in particular sets of daughter languages.
Read more about this topic: Proto-Austronesian Language