Two experiments with 40 children (grades 4 to 8) found the children often used their knowledge of derivational suffixes in defining low-frequency derivatives, and knowledge of suffixes was significantly correlated with suffix production in a nonsense task. The children's morphological awareness of derivational suffixes included semantic…

Comparison of English past-tense productivity in 31 school-age children with specific language impairment (SLI) and 31 children with no language (NL) impairment found SLI children made more errors, with a greater proportion resulting from overuse of unmarked grammatical forms (e.g., "go") than from suffixation (e.g., "goed"). Children with SLI…

This study compared the effect of productivity (a correlate of suffix frequency) on derivational suffix use in 69 elementary and middle school students' derivational suffix use. Twenty-three students had language-learning disabilities (LLD). Students with and without LLD used highly productive suffixes but LLD students were less accurate in…

Normal students (N=65) in fourth, sixth, and eighth grades were compared to 17 learning-disabled ninth graders on learning derivational morphology and spelling derived forms. Disabled students' knowledge of derivational morphology was equivalent to that of normal sixth graders, but spelling of derived forms was equivalent to that of fourth…