漢数字
Several Kra languages have regionally unusual consonant clusters and sesquisyllabic or disyllabic words, whereas other Kra–Dai languages tend to have only have single syllables. The disyllables in Buyang have been used by Sagart (2004) to support the view that the Kra-Dai languages are a subgroup within the Austronesian family. Unlike the Tai and Kam–Sui languages, most Kra languages, including Gelao and Buyang, have preserved the proto-Kra–Dai numerical systems. The only other Kra–Dai branch that preserves this is Hlai. Most other Kra–Dai languages adopted Chinese numerals over 1000 years ago.