Mainland Southeast Asia linguistic area

The Mainland Southeast Asia linguistic area is a sprachbund including languages of the Sino-Tibetan, Hmong–Mien (or Miao–Yao), Kra–Dai, Austronesian and Austroasiatic families spoken in an area stretching from Thailand to China.^[1] Neighbouring languages across these families, though presumed unrelated, often have similar typological features, which are believed to have spread by diffusion.^[2] James Matisoff referred to this area as the "Sinosphere", contrasted with the "Indosphere", but viewed it as a zone of mutual influence in the ancient period.^[3]