Emergence of the tone system in the Sanjiazi dialect of Manchu

In Sanjiazi Manchu, the pitch of unaccented syllables can be predicted, but accented syllables show four different kinds of pitch (high, low, rising and falling) which cannot be predicted. Therefore, four tonemes will be set up for the pitches of the accented syllables. The emergence of the low tone is very likely to have been caused by accent shift, which made unaccented syllables with a non-high pitch acquire accent without changing their pitch. The accent shift is likely to have been caused by two factors: (i) the difference in sonority between the formerly accented syllable and the currently accented syllable, or (ii) the fusion of the two syllables.