1 Introduction to Language Acquisition Theory Janet Dean Fodor St. Petersburg July 2013 Class 8. Implications and further questions Class 8. Implications and further questions

Summary: 50 years of learnability research  At the outset: Exciting discovery that natural languages have a formal structure that can be studied mathematically, as linguistic systems and also as targets of learning.  Then the surge in descriptive and theoretical linguistics, uncovering intricate properties peculiar to natural language.  So learnability theory undertook to show how rich grammars could be acquired from the impoverished input accessible to children. Syntax acquisition as ‘merely’ parameter setting.  Standard computer science methods were applied in modeling parameter setting. No more formal proofs, but simulation studies to test models.  Psychological feasibility has been the last part of the program to fall into place. 2

Next challenge - biolinguistic speculations  For linguists continuing in the TG tradition, emphasis has shifted again, now to the ‘biolinguistic perspective’.  It conceives the human language faculty as a mental organ, functioning in concert with other biological (perceptual and conceptual) systems (Hauser, Chomsky & Fitch, 2002).  Its evolution has become a focus of speculation.  The (apparent / alleged) rapidity of its evolution has led to a radical attempt to minimize the amount of language- specific apparatus that must be assumed to have evolved for human language to be possible. Just one mutation!  This is the driving force for the Minimalist Program. Ideally, no innate mechanisms specific to language, except: Combine expressions recursively. (Merge!) 3

Whether you agree with that or not…  The view of grammar acquisition as continuous with sentence processing is compatible with this eliminative approach.  It posits no learning mechanism other than is inherent in the ability to produce and understand language – even if no learning were required at all.  No need to assume the parallel evolution of a dedicated Language Acquisition Device (LAD), a mental component/procedure specifically designed and motivated to perform language acquisition.  It also offers a potential source of so-called ‘third factor’ influences, since sentence processing is known to exhibit economy tendencies, e.g., Minimal Attachment and the Minimal Chain Principle; also frequency sensitivity, etc. 4

Unifying psycholinguistics  Language acquisition and sentence processing have traditionally been separate wings of psycholinguistic research. But now they are close relations.  Chomsky (1965) portrays a child as trying to develop a theory of the internal rules/principles that allow adults to produce the sentences they do.  We assume that a child’s goal is to understand those sentences, as part of normal social interaction: What is Mommy saying to me?  The learning is incidental to that. ( But why not equally for L2? )  A learner adopts an I-level parameter value just in case it solves a specific parsing problem that s/he has encountered in comprehending E-level sentences.  Relating I-language to E-language is what’s challenging. 5

Relating I-language and E-language Relating I-language and E-language  I-language expressions are structured entities. Also, they may contain phonologically empty categories, such as ellipsis sites or traces of displaced constituents.  So I-language is not directly observable in the E-language word strings that constitute a child’s primary linguistic data.  A learner hearing an E-trigger (e.g., a word string with a preposition with no adjacent NP) must somehow recognize it as a manifestation of the abstractly specified I-trigger.  This I-E relation is the distinctively linguistic learnability issue. (Could it be acquired by domain-general learning?)  Our proposal: The parser provides the link between E and I.  This is exactly what the parser does all the time, in adult sentence processing. (Parser is generally assumed innate.) 6

Not tied to any one linguistic theory  We’ve couched this learning model in GB terms – old!  But the learning-by-parsing approach is not tied to any particular set of assumptions about syntactic structures or the nature of parameters (e.g., pairs of competing treelets), or even about how parsing proceeds.  Whether they are called parameters or not, the structural elements that can vary from one language to another are what a learner must choose among.  The one key requirement is that a parameter value is not an anonymous 0 or 1 from the learner’s perspective, but is an integral part of the structure of a sentence.  This is compatible with a wide swath of current linguistic theories, though they differ greatly with respect to the form of grammars and the contents of UG. HPSG, TAG, MP…. 7

Compatible with current transformational theory  The Minimalist Program has parametric treelets, the smallest possible: one feature.  The active elements that shape its syntactic derivations are individual formal features (e.g., case features, Tense, EPP).  The ‘probe-goal’ apparatus is the driving force of MP derivations. It establishes Agree relations between pairs of syntactic elements (a probe and a goal), under which they supply needed values for each other’s unvalued features.  In order for this to occur, a goal constituent (e.g., a wh- phrase) must in some cases move to the neighborhood of the element that is probing for it (e.g., a C[+Q]).  Whether it must move depends on whether the probe has a ‘strong’ feature (or ‘EPP’ or ‘edge’ feature). That can vary from language to language. A parameter. 8

Your questions 9