Linguistic phenomena as manifested in the case of a Hebrew-speaking aphasic are discussed in this monograph. The patient's linguistic performance included: (1)writing down forms which deviated from the standard orthography, but which corresponded remarkably well with the types of underlying phonological repre sentation that a linguist might independently propose; (2) verbal behavior which involved the frequently random transfer of verbs from one class to another; (3) restructuring of surface forms to form "novelroots; (4) errors involving the complex rule of spirantization. Attention is paid to the implications for linguistic research in general, and for Semitic in particular.