The book examines the way truth – value changes in English conditional sentences. It also determines the role of conditionals in ascertaining the truth - value of English conditional sentences.The approach is semantics. The analysis of some of the samples collected was based on Tarski''s theory of analysing truth – value in English conditional sentences. The study has four chapters. Chapter One deals the aim and objectives of the study, the approach adopted and the methodology. The approach adopted is that of Semantics. Chapter Two is the literature review. The views of major scholars on truth-conditional and truth-functional semantics is examined. Scholars'' views on issues like concepts, proposition, definite descriptions, sense, denotation, connotation, antonymy, synonymy, hyponymy, modality and conditional sentences, modal verbs and conditional clauses, hypothetical and counterfactualconditionals are discussed. Chapter three deals with the analysis and interpretation of data.Chapter Four summarizes major findings of the study.