KNOWLEDGE OF DERIVATIONAL SUFFIXES IN STUDENTS WITH LANGUAGE-LEARNINGDISABILITIES

Knowledge of derivational suffix meanings was investigated in 10- to 1 2-year-old students with language learning disabilities and individual ly matched chronological- and language-age peers. Students produced de rived forms from nonce bases in an elicitation task and selected deriv ed forms in a forced choice task. For instance, students produced a wo rd to label the baby of an invented animal called a TEM (TEMlet, TEMet te, TEMkin, etc.) and chose an appropriate label from four options (TE Mlet, TEMkin, TEMship, TEMhood). Twenty-eight suffixes (e.g., less, y, ize) conveying seven derivational meanings (e.g., ''without X,'' ''ap proximately X,'' ''to make X'') were studied. All groups showed higher accuracy on the forced choice task than on the elicitation task. Howe ver, elicitation task accuracy of students with language learning disa bilities fell substantially below that of typically achieving students . Suffixes for ''agent X,'' ''character of X,'' and ''to make X'' were produced in the elicitation task with higher accuracy than suffixes f or ''approximately X,'' ''diminutive X,'' and ''state of X.'' In both tasks, suffix use was associated with productivity (i.e., regularity o f suffix attachment). All groups chose highly productive suffixes (e.g ., TEMlet) over less productive suffixes (e.g., TEMkin) to convey each meaning.