Batak languages
The Batak languages are a subgroup of the Austronesian languages spoken by the Batak people in the Indonesian province of North Sumatra and surrounding areas.
Internal classification
The Batak languages can be divided into two main branches, Northern Batak and Southern Batak. Simalungun was long considered an intermediary, but in current classifications it is recognized as part of the Southern branch. Within Northern Batak, a study noted 80% cognate words between Karo and Alas, 81% with Pakpak, 76% with Simalungun & Toba, and 30% with Malay. Karo and Toba Batak are mutually unintelligible.Mandailing, Toba and Angkola are related to each other and mutually intelligible. Karo languages
are mutually intelligible with other Northern Batak languages named Alas – Kluet language's in the southern part of Aceh, and are also partially mutually intelligible with Pakpak and Singkil. Some Pakpak dialect also partially mutually intelligible with Toba languages. Simalungun languages are sometimes partially mutually intelligible with both Northern and Southern Batak, but more comprehensible with other Southern Batak languages. The geographical influences on the Batak languages can be seen in the map in the infobox; Lake Toba separates the Karo from direct contact with the Toba.
Reconstruction
The Batak languages can be shown to descend from a hypothetical common ancestor, Proto-Batak. The sound system of Proto-Batak was reconstructed by Adelaar.| Front | Central | Back | |
| High | *i | *u | |
| Mid | *ə | ||
| Low | *a |
Final diphthongs: *-uy, *-ey, *-ow.
The Proto-Batak sounds underwent the following changes in the individual daughter languages:
- Proto-Batak *k became h in initial and medial position in the Southern Batak languages:
- Proto-Batak *h was lost in Toba, Angkola and Mandailing:
- Proto-Batak final voiced stops *b, *d, and *g are retained only in Simalungun. In Toba, Angkola and Mandailing, they are unvoiced, while in the Northern Batak languages, they changed to homorganic nasals :
- The central vowel *ə is retained in the Northern languages, and shifted to /o/ in the Southern languages:
- Proto-Batak diphthongs are only retained in Simalungun, but shifted to monophthongs in all other Batak languages: