The
Mainland Southeast Asia (MSEA) linguistic area is a
linguistic area that stretches from Thailand to China and is home to speakers of languages of the
Sino-Tibetan,
Hmong–Mien (or Miao–Yao),
Tai–Kadai,
Austronesian (represented by
Chamic) and
Austroasiatic families. Neighbouring languages across these families, though presumed unrelated, often have similar typological features, which are believed to have spread by diffusion.
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.