The Proposition Bank project aims to enhance the Penn Treebank by adding semantic role labels to syntactic structures, providing a broad-coverage annotated corpus of semantic roles for verbs. This approach is practical for representing semantic information without delving into complex phenomena like coreference and quantification. The project defines a set of underlying semantic roles for each verb and annotates these roles in the Penn Treebank text. The annotation process involves a rule-based tagger followed by manual correction, ensuring consistency across verbs. The project focuses on verb-specific numbered roles and general adjunct-like arguments, distinguishing framesets based on semantic and syntactic criteria. The Proposition Bank aims to improve natural language understanding systems by providing a domain-independent resource for studying syntactic alternations and their impact on language processing. The article discusses the criteria for defining semantic roles, the annotation process, and comparisons with other projects like FrameNet.The Proposition Bank project aims to enhance the Penn Treebank by adding semantic role labels to syntactic structures, providing a broad-coverage annotated corpus of semantic roles for verbs. This approach is practical for representing semantic information without delving into complex phenomena like coreference and quantification. The project defines a set of underlying semantic roles for each verb and annotates these roles in the Penn Treebank text. The annotation process involves a rule-based tagger followed by manual correction, ensuring consistency across verbs. The project focuses on verb-specific numbered roles and general adjunct-like arguments, distinguishing framesets based on semantic and syntactic criteria. The Proposition Bank aims to improve natural language understanding systems by providing a domain-independent resource for studying syntactic alternations and their impact on language processing. The article discusses the criteria for defining semantic roles, the annotation process, and comparisons with other projects like FrameNet.