Published online by Cambridge University Press: 26 September 2008
It is argued that previous assessments of children's knowledge of the hard to see type of construction were confounded by a variety of extra-linguistic factors. Therefore, the relatively delayed age of comprehension previously reported (6½–8 years) may have been due to younger children's deficiencies in extralinguistic skills. In the present study, with these extralinguistic complications eliminated, the passing age was found to be 5 years, and even 4-year-olds evidenced considerable knowledge of the target structure. Other findings were: variation in sentence difficulty as a function of the syntactic and/or aspectual character of the verb; high test–retest reliability at all levels of performance; and a necessary-but-not-sufficient empirical relation between comprehension of the target construction and the passive. Results are discussed in terms of their implications for the acquisition of this particular structure and for the general problem of detecting linguistic competence from performance.
This research was supported by a predoctoral traineeship awarded to the first author by the Institute of Human Learning, University of California, Berkeley (NIGMS 5-T01-GM01207-14) and by the second author's appointment at the Institute of Human Development, University of California, Berkeley. Thanks are due to Ms Melinda Martin of the Albany Children's Center for her cooperation. Portions of this paper were presented at the Second Annual Boston University Conference on Language Acquisition, October 1977. Authors' address: Department of Educational Psychology, University of California, Berkeley, California 94720.