This study examines the relationship between third person singular
(3Psg) subject pronoun case and agreement, focusing on the hypothesis
that these two grammatical subsystems develop together. This hypothesis
is broken down into two separate, empirically testable hypotheses:
(a) that correct subject case pronoun production and the
production of agreement are correlated, and (b) that at the sentence
level, correct case is dependent on the presence of agreement. Twenty-nine children between the ages of 2;6 and 4;0 were each audiotaped for
approximately two hours playing and interacting with their primary
caregivers. Transcribed production data showed that 3Psg masculine
subject pronoun case was correlated with agreement marking, whereas
3Psg feminine subject pronoun case was not. This result suggests the
influence of a retrieval factor, termed the DOUBLE-CELL EFFECT, on the her
for she pronoun case error. At the utterance level, pronoun case was
independent of the presence of agreement. Overall, the study indicates
that the relationship between case and agreement may be discernible as
a general correlation, yet indiscernible at the level of sentence production.