Introduction The clinical syndrome of agrammatism has been and remains a unique window into the neurobiological mechanisms involved in morpho-syntactic processing. In the last two decades, the ability to study the neural correlates of language has been augmented by the contributions of functional neuroimaging, allowing investigation of the patterns of brain activity associated with specifi c morpho-syntactic processes in the normal brain. The imaging fi ndings, supplemented by the results of sophisticated neurophysiological investigations, which provide temporal information about brain processes, have produced a complex pattern of results, which go much beyond the simplistic idea of a localized “syntactic area” in the human brain. Backed by this corpus of new knowledge, lesion data derived from investigation of patients with morpho-syntactic disorders again become central in constraining the interpretation of results derived from the study of the neural correlates of language processing in the normal brain.