Knowledge of derivational suffixes in students with language learning disabilities

Knowledge of derivational suffix meanings was investigated in 10- to 12-year-old students with language learning disabilities and individually matched chronological- and language-age peers. Students produced derived forms from nonce bases in an elicitation task and selected derived forms in a forced choice task. For instance, students produced a word to label the baby of an invented animal called a TEM (TEMlet, TEMette, TEMkin, etc.) and chose an appropriate label from four options (TEMlet, TEMkin, TEMship, TEMhood). Twenty-eight suffixes (e.g., less, y, ize) conveying seven derivational meanings (e.g., "without X," "approximately X," "to make X") were studied. All groups showed higher accuracy on the forced choice task than on the elicitation task. However, elicitation task accuracy of students with language learning disabilities 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 for "approximately X," "diminutive X," and "state of X." In both tasks, suffix use was associated with productivity (i.e., regularity of suffix attachment). All groups chose highly productive suffixes (e.g., TEMlet) over less productive suffixes (e.g., TEMkin) to convey each meaning.