Error analysis concerns the investigation of negative influences on the foreign language learning process. Errors are usually thought of as caused by interference from the native language to the target language. In this article it is shown that interference occurs in the other direction as well, i.e. from language 2 to language 1. Jakobovits has termed this "backlash interference." Several examples of English sentences translated into German by German students learning English serve to illustrate the influence of English on the German translation. It is hard to decide whether an error is due to lack of understanding of language 2 or to the impossibility of transfer of concepts from one culture to another, what has been called "psychic distance" in bilingualism. Compared to contrastive analysis, error analysis is deemed more useful for the language classroom since it is based on actual occurrence rather than theory and is therefore attainable by student and teacher alike. A target to source language interference analysis would have the following advantages: (1) the analysis of transfer processes would help in positing an interlingual performance theory, (2) an error typology and hierarchy could be set up which would be both linguistically and pedagogically relevant, and (3) the language learner would acquire a workable attitude toward problem-solving procedures. (TL)