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Reid (1991) has suggested that the Central Cordilleran languages are most closely related to the Southern Cordilleran languages, which is supported by numerous exclusively shared innovations listed by Himes (2005).
Proto-Central Cordilleran can be reconstructed with phonemic stress.
Vocabulary
The comparison table (taken from Reid (1974) illustrates the correspondences between the Central Cordilleran languages, including inherited vocabulary as well as Central Cordilleran innovations.
^ Reid, Lawrence A. (1974). "The Central Cordilleran Subgroup of Philippine Languages". Oceanic Linguistics. 13 (1/2): 511–560. doi:10.2307/3622752. hdl:10125/32979. JSTOR3622752.
^ Himes, Ronald S. 2005. The Meso-Cordilleran Group of Philippine Languages. In Hsiu-chuan Liao and Carl R. Galvez Rubino (eds.), Current Issues in Philippine Linguistics and Anthropology: Parangal kay Lawrence A. Reid, 81-92. Manila, Philippines: Linguistic Society of the Philippines and SIL Philippines.
Reid, Lawrence A. (1991). "The Alta languages of the Philippines". In Ray Harlow (ed.). VICAL 2, Western Austronesian and Contact Languages. Papers from the Fifth International Conference on Austronesian Linguistics. Auckland: Linguistic Society of New Zealand. pp. 265–297.
Reid, Lawrence A. (2006). "On reconstructing the morphosyntax of Proto-Northern Luzon, Philippines". Philippine Journal of Linguistics. 37: 1–64.