Input Distribution Influences Degree of Auxiliary Use by Children with Specific Language Impairment

Area of Science:

• Linguistics
• Developmental Psychology
• Child Language Acquisition

Background:

• Children with specific language impairment (SLI) exhibit prolonged difficulties with tense and agreement morphemes.
• Understanding the source of these grammatical errors is crucial for effective intervention.

Purpose of the Study:

• To investigate if specific syntactic structures in language input contribute to the inconsistent morpheme use in children with SLI.
• To examine whether misinterpretations of nonfinite verb clauses affect grammatical accuracy.

Main Methods:

• Study 1: Preschoolers with SLI and typically developing peers were exposed to sentences with novel verbs in different syntactic contexts (auxiliary 'was' vs. nonfinite subject-verb sequences).
• Production tasks then assessed their use of the novel verbs with the auxiliary 'is'.
• Study 2: Comprehension of complex sentences with embedded nonfinite clauses was evaluated in children with SLI and controls.

Main Results:

• Children with SLI demonstrated lower accuracy in using novel verbs compared to peers.
• SLI group more frequently omitted the auxiliary 'is' when verbs were previously heard in nonfinite structures.
• In comprehension tasks, children with SLI were disproportionately affected by nonfinite clauses at sentence end.

Conclusions:

• Findings suggest that syntactic complexity, particularly nonfinite verb constructions, poses challenges for children with SLI.
• These misinterpretations likely contribute to the protracted difficulties with tense/agreement morphemes observed in SLI.
• Results support a construction learning framework for understanding language acquisition in SLI.