A longitudinal linguistic analysis of a 6-year-old boy (GA) with an acquired epileptic aphasia (‘‘Landau–Kleffner Syndrome''; LKS) was conducted to determine in what ways language breakdown and recovery occur. Language comprehension and production at the syllabic, phonemic, lexical, and morphosyntactic levels were assessed shortly before, during the acute phase of the illness, and at recovery, which was very rapid. Results show that in the acute phase, GA presented not only an auditory agnosia for speech and nonspeech sounds but also provided strong evidence that in production, prosody and speech processing were impaired.