Abstract
This article deals with the problems of enabling computers to communicate with humans in natural languages, such as English and French, as distinguished from formal languages, such as BASIC and PASCAL. Major issues in natural-language processing are discussed by examining several experimental computer systems developed over the last decade. The intent of the authors is to demonstrate that natural-language processing techniques are useful now, to reveal the richness of the computations performed by human natural-language communicators, and to explain why the fluent use of natural language by machines remains an elusive aspiration.