Abstract
It is commonly believed that phonology, morphology, syntax, and
semantics are distinct modules of language, governed by very different
principles with little common ground. Nonetheless several approaches
(e.g. Government Phonology, Distributed Morphology) subscribe to the
idea that at least some of these language modules exhibit profound
parallels. Interestingly, recent findings in computational linguistics
corroborate this hypothesis: it seems that linguistic dependencies
belong to a small, heavily constrained region of the so-called
subregular hierarchy. If correct, this has far-reaching
typological implications, sheds new light on learnability issues, and
raises deep questions about the cognitive architecture of language.
The subregular hierarchy provides a system for classifying structural
dependencies according to their computational complexity and expressive
power. It turns out that linguistic dependencies largely cluster at the
lower end of the hierarchy, thanks to the limiting effects of the
locality conditions that they are subject to. This computational result
furnishes answers to a variety of seemingly unrelated questions, such as:
- Why is there no first-last harmony in phonology?
- Why are some prefixes and suffixes freely iterable, but no circumfixes?
- Why does no language have a monomorphemic version of the quantifier
an even number of?
- Why is syntactic movement upward rather than downward?
This is but the tip of a much larger iceberg. The predictions span
phonology, morphology, syntax, and semantics, and they even intersect
with psycho- and neurolinguistics. Computational linguists cannot do all
of this by themselves. Without the expertise of theoretical linguists,
it is impossible to fully explore the cognitive, typological, and
theoretical ramifications of this “subregular conspiracy”. If we want
to know how deep the rabbit hole goes, we have to go down there together.
@Misc{Graf17CLStalk,
author = {Graf, Thomas},
title = {It's a (Sub-)Regular Conspiracy: {L}ocality and Computation in Phonology, Morphology, Syntax, and Semantics},
year = {2017},
note = {Invited talk, {M}ay 25--27, {CLS}, {U}niversity of {C}hicago, {C}hicago, {IL}},
}