Kuczaj S A
J Psycholinguist Res. 1983 Jan;12(1):69-73. doi: 10.1007/BF01072714.
A case study is reported in which a child (3 years; 4 months old) who produced forms such as mell and kunk (for smell and skunk, respectively) was asked to choose between his own forms and correct forms in a comprehension task. The results demonstrate that the child understood the correct forms to be the correct forms, suggesting that the child had greater competence than performance in regard to these phonological forms.