completed a book manuscript that summarizes over 10 years of work on the
problem of rules and exceptions, core vs. periphery, and how children,
and a theory of language, approaches grammars that "leak" (Sapir). This
work will be published by the MIT Press in 2016 (evidently an Amazon
link is up.)
The initial goal was modest. In my earlier work (KLNL, Chapter 3), I reported evidence that children learn and organize irregular verbs by rules. For instance, a rule "Change Rime to ought" takes care of verbs such as catch, think, buy, bring, teach, seek, and verbs such as say-said, lose-lost, sleep-slept, etc. fall under the rule of Vowel Shortening triggered by suffixation, much like the well-studied cases in English morpho-phonology such as serene-serenity, nation-national. In other words, the traditional approach to irregular morphology with rules going back to Bloch (1947) and SPE is correct, and the holistic storage/retrieval account is incorrect.
But these results
raise a sharp question: How does the child figure out the "ought" rule
is applies to a fixed number of words whereas the "-ed" rule is general
and can apply to any verb. Children occasionally over-use the -ed rule (hold-holded)
but no one ever says hatch-haught on the analogy of catch-caught.
Given the ubiquity of exceptions in language, a general solution must be
found. Furthermore, some deficiencies in the
variational approach to language acquisition developed in KLNL
also call for a principled distinction between noise and exception in
the formal solution was worked out in 2002, it took many years to
understand the scope of problems at hand, and accumulate a large number
of cross-linguistic case studies. A brief outline is as follows.
Chapter 1: Border Wars
tension between rules and exceptions, and productivity, in language. Why
this has remained an unresolved question and how it has poisoned the
water for so long.
Chapter 2: The Indispensability of Rules
A review of statistical facts of language especially morphology and
children’s acquisition of morphology with focus on productivity.
Contrary to popular beliefs, productivity should be understood as a
categorical notion in language, judging from the now extensive
cross-linguistic studies of language acquisition.
Chapter 3: The Tipping Point
Using the Elsewhere Condition as a basic principle of language, as well as a performance/processing model, derive the mathematical principle of productivity, what I call the Tolerance Principle:
Chapter 4: Signal and Noise
A very detailed study of the acquisition of English inflectional
morphology and nominalization morphology, the treatment of metrical
stress in English and its acquisition, and the important case of German
noun plurals where a very small rule (‘add -s’) can be productive. The
entire discussion is driven by the equation, using child-directed
Chapter 5: When Language Fails
predicts complete lexicalization when the number of exceptions to a rule
exceeds the threshold. I show that this leads to morphological gaps:
without a productive rule, you only know the derived form if you hear it
otherwise ineffability arises. Detailed numerical studies for gaps in
Russian (Morris Halle's famous 1973 paper), English
“stride-strode-stridden” gap, Spanish verbal inflections in the third
conjugation, and the masc. sg. genitive in Polish and its acquisition.
The Tolerance Principle also provides an integrated theory of language
acquisition, variation, and change, in that it provides/predicts the
conditions under which language change is actuated. As a case study, the
theory explains why—and when—the so-called dative sickness in Icelandic
started to take shape in the late 19th century.
Chapter 6: The Logic of Evidence
A completely new
conceptualization of the indirect negative evidence business in language
acquisition, especially in syntax. Instead of thinking about retreating
from over-generalization, a derivative application of the Tolerance
Principle ensures that the child is much more careful before
generalizing. Shows how the learner may acquire that adjectives such as
“asleep” do not allow attributive in NPs (“*the asleep cat”), and how to
resolve Baker’s classic problem of dative construction acquisition (“*I
donated the museum a painting”). A critique of previous proposals,
including Bayesian models of inference, is also included.
Chapter 7: On Language Design
Summary. How the
current study impacts traditional problems in linguistics, and how it
leads to a simplification of the theory of UG and language
learning, with a reduced role for domain-specific innate knowledge
of language, leading to an arguably more plausible solution to the
problem of language evolution. A novel account of why language learning
must start small.