How did Javanese change the word for “thorn” to fit a two-syllable pattern?

Many Austronesian languages exhibit a strong preference for a disyllabic (two-syllable) canonical shape in their content words. When this preference is violated, languages often employ specific mechanisms to restore the two-syllable structure.

In the case of the Javanese word for “thorn,” which is əri, the word passed through a stage where it existed as the monosyllabic form ri. To align with the preferred disyllabic canonical shape, the language added a schwa—an indistinct mid-central vowel—to the beginning of the word, resulting in the two-syllable form əri.1