title: The acquisition of auxiliary syntax: a longitudinal elicitation study. Part 1: auxiliary BE.
abstract: OBJECTIVE
  The question of how and when English-speaking children acquire auxiliaries is the subject of extensive debate. Some researchers posit the existence of innately given Universal Grammar principles to guide acquisition, although some aspects of the auxiliary system must be learned from the input. Others suggest that auxiliaries can be learned without Universal Grammar, citing evidence of piecemeal learning in their support. This study represents a unique attempt to trace the development of auxiliary syntax by using a longitudinal elicitation methodology.
  
  
  METHODS
  Twelve English-speaking children participated in 3 tasks designed to elicit auxiliary BE in declaratives and yes/no and wh-questions. They completed each task 6 times in total between the ages of 2;10 (years;months) and 3;6.
  
  
  RESULTS
  The children's levels of correct use of 2 forms of BE (is, are) differed according to auxiliary form and sentence structure, and these relations changed over development. An analysis of the children's errors also revealed complex interactions between these factors.
  
  
  CONCLUSIONS
  These data are problematic for existing accounts of auxiliary acquisition and highlight the need for researchers working within both generativist and constructivist frameworks to develop more detailed theories of acquisition that directly predict the pattern of acquisition observed.
authors: University of Manchester, School of Psychological Sciences, Oxford Road, Manchester M139PL, UK. anna.theakston@manchester.ac.uk
authors: Anna L
authors: AL
authors: Theakston
authors: Caroline F
authors: CF
authors: Rowland
mesh_terms: D000375:Aging; D000704:Analysis of Variance; D002663:Child Language; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007807:Language Tests; D008037:Linguistics; D008137:Longitudinal Studies; D008297:Male; D015203:Reproducibility of Results; D013060:Speech