In this paper we present the Linguistic Analysis Component of a Spoken Dialogue System designed for robustness and flexibility. The dialogue takes place in the Greek Language through the public telephone network and is performed in two different applications. The analysis is based on Island Parsing, Pattern Matching and Frame-based Representation techniques. The main knowledge sources are a Semantic Network and Frame-Slot structures thoroughly connected with each other. Simple bigram grammar rules have been also used to assist the parsing process as well as to evaluate the recognition output.