The immediate objective of this course in technical English was to enable French-speaking mechanics and technicians to read the instructions for the installation, operation and upkeep of American-made machinery. Although the learners knew very little English, available British and American technical documents were used because of their authenticity and the possibility of defining learners' needs from the communicative objectives of the documents. While the workers could generally locate the information they needed, they could not comprehend it because of the complex discursive processes operative in the text. Contrary to the hypotheses formulated by most Anglo-Saxon theorists, difficulties connected with morpho-syntactic interpretation seem to be the crux of most problems in comprehension of written texts. Therefore, it was hypothesized that the learners could transfer some of their native language skills and understandings to English and the course could concentrate on difficulties in morpho-syntactic interpretation. The tentative conclusion is that learning to understand specialized writing requires learning a technique for structural decoding of utterances. To justify this view, three texts are analyzed from the point of view of structure and difficulties related to functional grammar, morphology and syntax. (AMH)