The Weekly Newsletter of MIT Linguistics

Ling-Lunch 10/20 — Alëna Aksënova (Stony Brook)

Speaker: Alëna Aksënova (Stony Brook)
Tittle: Morphotactics and phonology as subregular languages
Date: Thursday, October 20th
Time: 12:30pm-1:50pm
Location: 32-D461

The main idea of this talk is to show which formal language classes might be the best fit for phonology and morphotactics, and to show how certain typological gaps can be predicted by the characteristics of these formal languages.

For a long time it was assumed that both phonological and morphological patterns are regular (Kaplan & Kay 1994, Beesley & Karttunen 2003). Recently, Heinz (2011, 2012, 2013) showed that this characterization is too general: although the regular class is sufficiently expressive, it is not restrictive enough. For example, typologically non-existent patterns such as First-Last Harmony (harmony happens only between the first and the last vowel in a word) and Sour Grapes Harmony (harmony applies only if it can be applied to the whole word) are regular. Weaker formal languages classes are needed to accurately capture the computational properties of phonology.

Based on recent research (Aksënova et al. 2016) I argue that morphotactics does not require the whole power of regular languages, either. I show which subclasses of regular languages are needed to account for morphotactics, present specific typological gaps and derive them from rigorous computational complexity results. This computationally grounded approach to phonology and morphology also provides a new perspective on acquisition, and raises many new research questions.