Complex sentence: They speak the Mon language, an Austroasiatic language, and share a common origin with the Nyah Kur people of Thailand from the Mon mandala (polity) of Dvaravati.
Split into simpler sentences: They speak the Mon language, an Austroasiatic language, and share a common origin with the Nyah Kur people of Thailand. They are from the Mon mandala (polity) of Dvaravati.