Error analyses of compositions of native speakers of English learning German as a foreign language in a formal setting are generally designed to establish the major areas of weakness of relatively advanced and motivated learners who have achieved roughly equal levels of proficiency. To this end every error is analyzed and subsequently categorized, so that each type of errormorphological, lexical, syntactic or orthographiccan be stated as a percentage of all errors committed by the group of students as a whole. The number of such free writing exercises subjected to error analysis tends to be relatively low: Grauberg's' sample consisted of 23, and Rogers'2 sample, of 26 compositions. This study was made with a different set of criteria in mind. The objective was not to categorize each composition error, but to concentrate on those areas which experience suggested are major sources of error for American college students. In addition, it was decided to analyze writing samples of students of different rather than the same level of proficiency, and to establish the changes in the average error rate per student over a three-semester sequence. Since it seemed impractical to conduct a longitudinal study focusing on a small number of students over a period of one and a half years, a cross-sectional design was chosen instead. The second objective of the study was to establish the degree of negative transfer, i.e. interference, from English for each group, since there seems to be no consensus in the European and American literature on foreign language acquisition and error analysis regarding such transfer in adults learning a foreign language in a formal setting. In a number of American publications the majority of errors are ascribed to intralingual, i.e. developmental factors, while European studies find a much larger percentage to be the result of negative interlingual transfer. Dulay, Burt, and Krashen,3 for example, cite studies by Lococo, Valdman, and others in the United States and Canada which attribute only between 8% and 23% of all errors to negative transfer. Nickel4 and Hopkins,5 on the other hand, referring to Legenhausen and Arabski, estimate the percentage of such interlingual errors to lie between 30% and 50% of total errors committed by adult learners. Grauberg reports similar results in his analysis of errors made by advanced students at a British university who had studied German for at least four or five years prior to enrolling in his