Coverpage -- Serieseditor -- Titlepage -- Copyright -- Contents -- Acknowledgements -- List of Abbreviations -- Introduction -- Part 1: Lexical Competence and Lexical Errors -- 1 Vocabulary Acquisition in the Second Language -- Theories of Vocabulary Acquisition in the Second Language -- Vocabulary Acquisition by Young Learners -- L1 and L2 Vocabulary Acquisition: Similarities and Differences -- Conclusion -- 2 Variables Affecting Lexical Production -- Overview of Variables Affecting the Production of Vocabulary -- Proficiency Level -- Vocabulary Size -- Conclusion -- 3 Vocabulary and Writing -- Developing Writing Skills -- Assessing Writing -- Conclusion -- 4 Lexical Errors in SLA -- Definitions of 'Lexical Error' -- Taxonomies of Lexical Errors -- Lexical Errors as Evidence of Vocabulary Acquisition -- Lexical Errors in Communication -- Lexical Errors in the Educational Context -- Conclusion -- Part 2: Lexical Error Production in Young Spanish Learners' Written Compositions -- 5 Designing a Study to Explore Lexical Errors in Writing -- Research Questions and Hypotheses -- Design of the Study -- Participants -- Materials -- Procedures -- Analysis -- 6 Lexical Error Production: Changes Over Time -- Proficiency-Related Lexical Error Types -- Formal and Semantic Lexical Errors -- L1-Oriented and L2-Oriented Lexical Errors -- Discussion -- Conclusion -- 7 Lexical Errors in Writing Quality -- Lexical Errors as Predictors of the Quality of Written Composition -- Changes over Time in the Relationship between Lexical Errors and Essay Quality -- Discussion -- Conclusion -- 8 Lexical Errors and Receptive Vocabulary Knowledge -- Lexical Errors as Negative Indicators of Vocabulary Knowledge -- Discussion -- Conclusion -- 9 Some Concluding Remarks -- Pedagogical Implications -- Limitations of the Study -- Further Research -- Appendices -- References.