Spoken dialogue systems can be considered knowledge-based systems designed to interact with users using speech in order to provide information or carry out simple tasks. Current systems are restricted to well-known domains that provide knowledge about the words and sentences the users will likely utter. Basically, these systems rely on an input interface comprised of speech recogniser and semantic analyser, a dialogue manager, and an output interface comprised of response generator and speech synthesiser. As an attempt to enhance the performance of the input interface, this paper proposes a technique based on a new type of speech recogniser comprised of two modules. The first one is a standard speech recogniser that receives the sentence uttered by the user and generates a graph of words. The second module analyses the graph and produces the recognised sentence using the context knowledge provided by the current prompt of the system. We evaluated the performance of two input interface...