Abstract
Working with Portuguese learners of English has brought to my attention aconsiderable number of errors of English which have to do with my students´ priorknowledge of Portuguese. Identifying those errors and interpreting them in the light of contrastive linguistics can help indicating ways in which a Portuguese–Englishtranslation corpus can be harnessed to prepare English as a second language teachingmaterials for native speakers of Portuguese. This paper reports on a few typicalexamples of Portuguese-English crosslinguistic influence and explains how they can beused as a key to extracting from a Portuguese-English translation corpus comparablefacts of linguistic performance which are particularly relevant to Portuguese learners of English.