Brazilian educational system is faced with the task of promoting deaf people educational rights. Presently, the deaf are integrated in the classroom along with hearing students. Qualitative Reasoning may provide tools to support Portuguese acquisition in the context of the development of scientific concepts. This study describes an experiment with eight deaf students being exposed to three articulate qualitative models organized in gradual levels of complexity. Questionnaires were used to assess ther students' ability of expressing ideas in written Portuguese using the ontology provided by the models. An interesting result was that five students were consistent in the ability of recognizing objects and processes, build up causal chains and apply them to a given situation, assessing derivative values of quantities and making predictions about the consequences of changes, and write up a composition about an ecological accident, using linguistic descriptions of the relevant physical and social processes. These preliminary results are encouraging and ongoing work is the development of models and textual material in different domains, such as electrochemistry, to explore the potential of qualitative models in second language acquisition.