Introduction to Language Acquisition Theory Janet Dean Fodor St. Petersburg July 2013

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

2. 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.

3. 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

4. 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.

5. 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.

6. Relating I-language and E-language • I-language expressions are structured entities. Also, they may contain phonologically empty categories, such asellipsis 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.)

7. 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

8. 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.

9. Your questions