An Extended Optional Infinitive Stage in German-Speaking Children With Specific Language Impairment

Abstract

An extended period of Optional Infinitives (OIs) has been identified in young English-speaking children with specific language impairment (SLI; Rice and Wexler (1996b), Rice, Wexler, and Cleave (1995)). Poeppel and Wexler (1993) argued that an OI period exist in young unaffected German-speaking children. In this investigation, predictions are formulated for an extended OI stage in German-speaking children with SLI and evaluated in a clinical sample of 8 young German-speaking children with SLI, ages 4;0 to 4;8, and a control group of 8 younger mean length of utterance equivalent children, ages 2;1 to 2;7. Longitudinal spontaneous language samples reveal that the affected group was more likely than the younger control group to use infinitival lexical verbs in declarative sentences and to drop copular SEIN, as predicted for an Extended Optional Infinitive (EOI) stage. As expected, lexical infinitives appeared in clause-final word order, showing that the affected children know the association between sentence position and finiteness and do not show deviant word order in verb placement. The use of OIs in the SLI group cannot be attributed to missing agreement (as argued by Clahsen and colleagues) because the use of third-person -t appeared with third-person subjects in 94% of uses and forms of SEIN agreed with the subject in 98% of overt uses. Overall, the evidence provides strong support for an EOI period in German-speaking children with SLI. Individual children, as well as group data, show the expected patterns.