This thesis describes the design and implementation of a system called the Model Generator that graphically models digital system specifications expressed in English. This research is part of the ASPIN project which has a long-term goal of providing an automated system for digital system synthesis from informal specifications. Because of the versatility of the English language, there can be more than one interpretation of specification sentences. So before these specifications are synthesized into formal models, it is necessary to obtain validation of their interpretation from the specification author. The specification sentences are mapped into a common knowledge representation, called conceptual graphs, by first parsing and then semantically analyzing them. The Model Generator then uses the conceptual graphs to generate a graphical model representing the meaning of the English specification sentence. This is done in two stages. First, the commands for drawing the icons used for the graphical representation are assembled by consulting an Interpretation Library and a conceptual type hierarchy. In the second stage, the icons used in the representation are displayed using an X-Windows interface. The Model Generator has been implemented in the C programming language under the X-Windows environment. / Master of Science