Editing Sprachbund (section)

===Mainland Southeast Asia===
Languages of the [[Mainland Southeast Asia linguistic area]] have such great surface similarity that early linguists tended to group them all into a single family, although the modern consensus places them into numerous unrelated families. The area stretches from Thailand to China and is home to speakers of languages of the [[Sino-Tibetan languages|Sino-Tibetan]], [[Hmong–Mien]] (or Miao–Yao), [[Tai–Kadai languages|Tai–Kadai]], [[Austronesian languages|Austronesian]] (represented by [[Chamic]]) and [[Mon–Khmer]] families.<ref name="Enfield">{{cite journal
| title = Areal Linguistics and Mainland Southeast Asia | first = N. J. | last = Enfield | journal = Annual Review of Anthropology | volume = 34 | issue = 1 | year = 2005
| pages = 181–206 | doi = 10.1146/annurev.anthro.34.081804.120406 | hdl = 11858/00-001M-0000-0013-167B-C | url = http://pubman.mpdl.mpg.de/pubman/item/escidoc:57458:2/component/escidoc:57459/Enfield_2005_areal.pdf | hdl-access = free }}</ref>

Neighbouring languages across these families, though presumed unrelated, often have similar features, which are believed to have spread by diffusion.
A well-known example is the similar [[tone (linguistics)|tone]] systems in [[Sinitic languages]] (Sino-Tibetan), Hmong–Mien, [[Tai languages]] (Kadai) and [[Vietnamese language|Vietnamese]] (Austroasiatic). Most of these languages passed through an earlier stage with three tones on most syllables (but no tonal distinctions on [[checked syllable]]s ending in a [[stop consonant]]), which was followed by a [[tone split]] where the distinction between voiced and voiceless consonants disappeared but in compensation the number of tones doubled. These parallels led to confusion over the classification of these languages, until [[André-Georges Haudricourt]] showed in 1954 that tone was not an invariant feature, by demonstrating that Vietnamese tones corresponded to certain final consonants in other languages of the Mon–Khmer family, and proposed that tone in the other languages had a similar origin.<ref name="Enfield"/>

Similarly, the unrelated [[Khmer language|Khmer]] (Mon–Khmer), [[Cham language|Cham]] (Austronesian) and [[Lao language|Lao]] (Kadai) languages have almost identical vowel systems.
Many languages in the region are of the [[isolating languages|isolating]] (or analytic) type, with mostly monosyllabic morphemes and little use of [[inflection]] or [[affix]]es, though a number of Mon–Khmer languages have [[derivational morphology]].
Shared syntactic features include [[classifier (linguistics)|classifier]]s, [[OV language|object–verb order]] and [[topic–comment]] structure, though in each case there are exceptions in branches of one or more families.<ref name="Enfield"/>