Editing Language acquisition (section)

=== Merge (linguistics)-based theory ===
<!-- Maybe this is supposed to be a new section???  In any case, I did not understand this section, and suggest that someone familiar with the concepts and fluent in the English language review this. ~~~~ --><!-- This First sentence is too long.  -->
{{further|Merge (linguistics)}}
In bare-phrase structure ([[minimalist program]]), theory-internal considerations define the specifier position of an internal-merge projection (phases vP and CP) as the only type of host which could serve as potential landing-sites for move-based elements displaced from lower down within the base-generated VP structure—e.g. A-movement such as passives (["The apple was eaten by [John (ate the apple)"]]), or raising ["Some work does seem to remain [(There) does seem to remain (some work)"]]). As a consequence, any strong version of a structure building model of child language which calls for an exclusive "external-merge/argument structure stage" prior to an "internal-merge/scope-discourse related stage" would claim that young children's stage-1 utterances lack the ability to generate and host elements derived via movement operations. In terms of a merge-based theory of language acquisition,<ref>{{cite book|author1=Galasso, Joseph  |year=2016|title=From Merge to Move: A Minimalist Perspective on the Design of Language and its Role in Early Child Syntax|publisher=LINCOM Studies in Theoretical Linguistics 59}}).</ref> complements and specifiers are simply notations for first-merge (= "complement-of" [head-complement]), and later second-merge (= "specifier-of" [specifier-head], with merge always forming to a head. First-merge establishes only a set {a, b} and is not an ordered pair—e.g., an {N, N}-compound of 'boat-house' would allow the ambiguous readings of either 'a kind of house' and/or 'a kind of boat'. It is only with second-merge that order is derived out of a set {a {a, b}} which yields the recursive properties of syntax—e.g., a 'house-boat' {house {house, boat}} now reads unambiguously only as a 'kind of boat'. It is this property of recursion that allows for projection and labeling of a phrase to take place;<ref>{{cite book|author1=Moro, A.  |year=2000|title=Dynamic Antisymmetry, Linguistic Inquiry Monograph Series 38|publisher=MIT Press}}).</ref> in this case, that the Noun 'boat' is the Head of the compound, and 'house' acting as a kind of specifier/modifier. External-merge (first-merge) establishes substantive 'base structure' inherent to the VP, yielding theta/argument structure, and may go beyond the lexical-category VP to involve the functional-category light verb vP. Internal-merge (second-merge) establishes more formal aspects related to edge-properties of scope and discourse-related material pegged to CP. In a Phase-based theory, this twin vP/CP distinction follows the "duality of semantics" discussed within the Minimalist Program, and is further developed into a dual distinction regarding a probe-goal relation.<ref>{{cite book|author1=Miyagawa, Shigeru  |year=2010|title=Why Agree? Why Move?|publisher=MIT Press}}</ref> As a consequence, at the "external/first-merge-only" stage, young children would show an inability to interpret readings from a given ordered pair, since they would only have access to the mental parsing of a non-recursive set. (See Roeper for a full discussion of recursion in child language acquisition).<ref>{{cite book|author1=Roeper, Tom  |year=2007|title=The Prism of Grammar: How child language illuminates humanism|publisher=MIT Press}}).</ref> In addition to word-order violations, other more ubiquitous results of a first-merge stage would show that children's initial utterances lack the recursive properties of inflectional morphology, yielding a strict Non-inflectional stage-1, consistent with an incremental Structure-building model of child language.

Generative grammar, associated especially with the work of Noam Chomsky, is currently one of the approaches to explaining children's acquisition of syntax.<ref>{{cite book |author1=Lillo-Martin, Diane C. |author2=Crain, Stephen |title=An introduction to linguistic theory and language acquisition |publisher=Blackwell Publishers |location=Cambridge, MA |year=1999 |isbn=978-0-631-19536-8 |oclc=799714148 }}</ref> Its leading idea is that human biology imposes narrow constraints on the child's "hypothesis space" during language acquisition. In the principles and parameters framework, which has dominated generative syntax since Chomsky's (1980) ''[[Lectures on Government and Binding|Lectures on Government and Binding: The Pisa Lectures]]'', the acquisition of syntax resembles ordering from a menu: the human brain comes equipped with a limited set of choices from which the child selects the correct options by imitating the parents' speech while making use of the context.<ref>{{cite book |author=Baker, Mark Raphael |title=The atoms of language |publisher=Oxford University Press |location=Oxford [Oxfordshire] |year=2002 |isbn=978-0-19-860632-1 |oclc=66740160 }}</ref>

An important argument which favors the generative approach, is the [[poverty of the stimulus]] argument. The child's input (a finite number of sentences encountered by the child, together with information about the context in which they were uttered) is, in principle, compatible with an infinite number of conceivable grammars. Moreover, rarely can children rely on [[corrective feedback]] from adults when they make a grammatical error; adults generally respond and provide feedback regardless of whether a child's utterance was grammatical or not, and children have no way of discerning if a feedback response was intended to be a correction. Additionally, when children do understand that they are being corrected, they don't always reproduce accurate restatements.<!-- I changed "few" to "rarely", so that's the text that this "dubious" comment is referring to. ~~~~ -->{{Dubious|More than a few children can rely on corrective feedback|reason=Children can distinguish corrective feedback from other responses|date=May 2017}}<ref>{{cite journal |last1=Marcus |first1=Gary F. |title=Negative evidence in language acquisition |journal=Cognition |date=January 1993 |volume=46 |issue=1 |pages=53–85 |doi=10.1016/0010-0277(93)90022-n |pmid=8432090 }}</ref><ref>{{cite book |last1=Brown |first1=Roger |last2=Camile |first2=Hanlon |chapter=Derivational complexity and order of acquisition in child speech |pages=11–54 |editor1-last=Hayes |editor1-first=John R. |title=Cognition and the Development of Language |date=1970 |publisher=Wiley |isbn=978-0-471-36473-3 |oclc=577205221 }}</ref> Yet, barring situations of medical abnormality or extreme privation, all children in a given speech-community converge on very much the same grammar by the age of about five years. An especially dramatic example is provided by children who, for medical reasons, are unable to produce speech and, therefore, can never be corrected for a grammatical error but nonetheless, converge on the same grammar as their typically developing peers, according to comprehension-based tests of grammar.<ref>{{cite book|author=Lenneberg, Eric|year=1967|title=Biological Foundations of Language|location=New York|publisher=Wiley}}</ref><ref>{{cite conference|author=Stromswold, Karin|title=Lessons from a mute child|conference=Rich Languages from Poor Inputs: A Workshop in Honor of Carol Chomsky|location=MIT, Cambridge, MA|date=11 December 2009}}</ref>

Considerations such as those have led Chomsky, [[Jerry Fodor]], [[Eric Lenneberg]] and others to argue that the types of grammar the child needs to consider must be narrowly constrained by human biology (the nativist position).<ref name=Chomsky1975>{{cite book|author=Chomsky, N.|title=Reflections on Language|url=https://archive.org/details/reflectionsonlan00chom|url-access=registration|location=New York|publisher=Pantheon Books|year=1975}}</ref> These innate constraints are sometimes referred to as [[universal grammar]], the human "language faculty", or the "language instinct".<ref name=Pinker>{{cite book |author=Pinker, Steven |title=The Language Instinct: How the Mind Creates Language (P.S.) |publisher=Harper Perennial Modern Classics |year=2007 |isbn=978-0-06-133646-1 |oclc=778413074 }}</ref>