Object-oriented analysis and design has become a major approach in the design of software systems. Recent developments in CASE tools provide help in documenting the analysis and design stages and in detecting incompleteness and inconsistency in analysis. However, these tools do not contribute to the initial and difficult stage of the analysis process of identifying the objects/classes, attributes and relationships used to model the problem domain. This paper presents a tool, Class-Gen, which can partially automate the identification of objects/classes from natural language requirement specifications for object identification. Use case descriptions (UCDs) provide the input to Class-Gen which parses and analyzes the text written in English. A parsed use case description (PUCD) is generated which is then used as the basis for the construction of an initial UML class model representing object classes and relationships identified in the requirements. PUCDs enable the extraction of nouns, verbs, adjectives and adverbs from traditional UCDs for the identification process. Finally Class-Gen allows the initial class model to be refined manually. Class-Gen has been evaluated against a collection of unseen requirements. The results of the evaluation are encouraging as they demonstrate the potential for such tools to assist with the software development process.