ABSTRACTThis study investigated the hypothesis that children with a reading disability understand and use sound-spelling correspondence rules less frequently in spelling than children with other learning disabilities and normally achieving children. To test this hypothesis, spelling errors of children between the ages of 6 and 16 with a reading disability (RD), an arithmetic disability (AD), and normally achieving children (NA) were examined. Two groups of children with an arithmetic disability were included: those with good spelling skills (AD-good), and those with poor spelling skills (AD-poor). The accuracy of the spelling errors according to sound-spelling correspondence rules (phonological accuracy) of the children was determined using both a constrained system (inclusion of position cues) and an unconstrained system (in which positional cues were irrelevant). The visual similarity of the error to the target word was also determined. The RD group at all ages produced significantly fewer phonologically accurate misspellings than the children with normal achievement scores, whether the constrained or the unconstrained scoring system was used. The AD-poor spellers and the RD group produced significantly fewer phonologically constrained, accurate misspellings than the NA group. Using the unconstrained measure, the AD-poor spellers at the youngest age level displayed as much difficulty using rudimentary sound-symbol conversion rules as the RD group, while at the older age levels, they did as well as the NA group. AD-good spellers performed as well as the NA group on both measures at all age levels. Children who were good readers and spellers (Good RS) were compared with children who were poor readers and spellers (Poor RS) and with children who were good readers and poor spellers (Mixed RS). Mixed RS produced significantly more phonologically and visually accurate misspellings than Poor RS. In summary, subtypes of learning-disabled children use spelling strategies that are significantly different from each other. RD children have the most difficulty acquiring the knowledge of soundspelling correspondence rules that are necessary for English spelling skills. The performance of AD children depends on the complexity of the scoring system, age, and spelling ability. Those students whose knowledge of sound-spelling correspondence rules is sufficiently well developed for reading but not for spelling (good readers/poor spellers) develop their phonetic skills more slowly than the good readers/good spellers. The understanding and use of phonological rules varies according to the subtype of learning disability, with children with a reading disability performing the most poorly at all age levels.