Aslian languages recognized by the Malaysian administration include Kensiu, Kintaq, Jahai, Minriq, Batek, Cheq Wong, Lanoh, Temiar, Semai, Jah Hut, Mah Meri, Semaq Beri, Semelai and Temoq.

[1] Aslian languages originally appeared on the western side of the main mountains and eventually spread eastwards into Kelantan, Terengganu and Pahang.

[3] There is a possibility the early Monic and Nicobarese people had contact with the migrants who moved into the Malay Peninsula from further north.

Sidwell (2023) proposed that Proto-Aslian had arrived in the Malay Peninsula from the Gulf of Thailand region prior to Mon dominance, and was part of an early southern dispersal that also included Nicobaric.

Due to its early split from the rest of Austroasiatic, Aslian contains many retentions and has escaped the areal influences that had later swept mainland Southeast Asia.

The loss of vowel length must have led to complex reorganizations in the vocalic systems of the affected languages, by developing new contrasts elsewhere.

Aslian syntax is presumably conservative with respect to Austroasiatic as a whole, though Malay influence is apparent in some details of the grammar (e.g. use of numeral classifiers).

This manifests itself in their elaborate pronominal systems, which make inclusive/exclusive and dual/plural distinctions, and take the trouble to reflect the person and number of the subject by a prefixal concordpronoun on the verb.

[1] Austroasiatic languages have a penchant for encoding semantically complex ideas into unanalyzable, monomorphemic lexemes e.g. Semai thãʔ 'to make fun of elders sexually'.

Lexicon elaboration is particularly great in areas which reflect the interaction of the Aslians with their natural environment (plant and animal nomenclature, swidden agriculture terminology etc.).

[22] Expressives are words which describe sounds, visual phenomena, bodily sensations, emotions, smells, tastes etc., with minute precision and specificity.

Unlike nouns and verbs, expressives are lexically non-discrete, in that they are subject to a virtually unlimited number of semantic nuancings that are conveyed by small changes in their pronunciation.

There was a possibility that migrants from Borneo settled in the Malay Peninsula 3000–4000 years ago and established cultural dominance over the Aslian speakers.

[2] All Aslian languages are endangered as they are spoken by a small group of people, with contributing factors including speaker deaths and linguistic assimilation with the Malay community.

[2] Some Aslian languages are already extinct, such as Wila' (also called Bila' or Lowland Semang), which was recorded having been spoken on the Province Wellesley coast opposite Penang in the early 19th century.