The nature of common language errors for learners of second languages is explored, and it is found that the errors cannot adequately be explained in terms of the theory of language interference. A new rationale for these errors can come from an investigation of the perceptual strategies common to error analysis, and thus it is postulated that researchers and educators should shift their emphasis away from interference theory toward error analysis theory. One of the immediate consequences of promoting the error analysis theory is that language teachers must be made aware of the role that the processes of lexical incorporation, inchoation, and causation play in the acquisition of language. Another consequence lies in the realization that language teachers must provide the learner with pertinent semantic information in order to allow him to adequately process speech events. (Author/LG)