Children's comprehension and production of derivational suffixes.

Relational knowledge of 21 derivational suffixes conveying six different meanings was investigated with 120 children from 3rd to 8th grade, and with 40 adults. The results obtained from a nonsense-word paradigm indicated that suffixes were comprehended with greater accuracy than they were produced, particularly by the children. Children in the 5th through 8th grades were more accurate than children in the 3rd and 4th grades in both suffix comprehension and production. Children and adults demonstrated greatest accuracy in both comprehension and production with the meaning "without X" (conveyed by the suffix less). Overall, they showed low comprehension accuracy with a diminutive suffix, ette, and the suffix ful, meaning "character of X." They showed low production accuracy with "can be Xed" (able). Productive suffixes were produced more frequently than less productive suffixes to convey a given meaning.