List of Tables and Figures -- Abbreviations and Conventions -- 1. Introduction -- 2. Lexical-Semantic and Syntactic Aspects of Factivity -- 2.1 Introduction -- 2.2 A Lexical-Semantic Account of Factivity: Kiparsky & Kiparsky (1971) -- 2.3 Complement Clauses in Factive Sentences -- 2.4 A Semantic-Syntactic Account of Factivity -- 2.5 Semantic-Syntactic versus Pragmatic Factivity -- 2.6 P-factive and Nonfactive Matrix Predicates -- 2.7 Conclusion -- 3. Presupposition and Factivity -- 3.1 Introduction -- 3.2 Semantic and Pragmatic Inferences -- 3.3 Identifying Presuppositions in Factive Complements -- 3.4 A Discourse-Semantic Approach to Presupposition: File Change Semantics -- 3.5 Conclusion -- 4. The Structure of Factive and Nonfactive Sentences -- 4.1 Introduction -- 4.2 Syntactic Restrictions for Factive Sentences -- 4.3 Reflection of Factivity in the Complements' Event Structure -- 4.4 Widening the Perspective: Response Stance Complements -- 4.5 Conclusion -- 5. Factivity in Language Acquisition -- 5.1 Introduction -- 5.2 Hypotheses for Language Acquisition -- 5.3 Language Acquisition Data: Two Caveats -- 5.4 Acquisition of Complex Clauses -- 5.5 Cognitive Aspects of Mastering Factivity: Theory of Mind -- 5.6 Comprehension of P-factive and Nonfactive Verbs -- 5.7 Mastering Weak Island Effects of Factive Sentences -- 5.8 Conclusion -- 6. Towards a Developmental Model -- 6.1 Introduction -- 6.2 The Psycholinguistic Perspective -- 6.3 Acquiring Factivity: A Developmental Path -- 6.4 Conclusion -- 7. Experimental Studies -- 7.1 Introduction -- 7.2 Rationale of the Experimental Studies -- 7.3 Experiment 1 -- 7.4 Experiment 2 -- 7.5 General Discussion -- 7.6 The Developmental Path Recasted -- 7.7 Conclusion -- 8. Conclusion -- Appendix -- References.