In Zimbabwe, university students continue to have problems with scientific communication despite the fact that English is a widely-used second language and students have received most formal science instruction in English. However, the problems differ from those of both students of English as a foreign language and students studying their first language. Problems are more commonly performance than competence errors, and students' language skills need to be developed in tandem with their cognitive skills. Students exhibit a variety of problems in expressing scientific propositions appropriately. They frequently make propositions that are inaccurate because they are expressed with an inappropriate degree of generalization, usually overgeneralizing. Students may overqualify a theory or use unnecessary conditionals, suggesting lack of confidence in some generalizations. They may also have difficulty expressing indefinite reference in a generalization or expressing the relationship between theoretical predictions and experimental results. Some of the problems are primarily linguistic, but many relate to the requirements of scientific discourse as it embodies scientific method. English for science and technology must be taught as an extension of science education. (MSE)