Chapter 1 The Present State of Research on Discourse Markers 1.1 Introduction 1.2 Discourse Markers in Previous Studies 1.2.1 Diversity in Terminology and Definition 1.2.2 Theoretical Approaches 1.2.2.1 Pragmatic Perspective 1.2.2.2 Relevance Theoretic Approach 1.2.2.3 Coherence-based Functional Approach 1.2.2.4 Aijmer' s Functional Perspective 1.2.2.5 Diachronic Approach 1.2.3 Functional Domains of Discourse Markers 1.3 Overview of the Current Study 1.3.1 A Corpus-linguistic Approach 1.3.2 The Corpus Used in This Research 1.3.3 Outline of This Study 1.3.4 Significance of This StudyChapter 2 Conceptual Background of the Current Study 2.1 Introduction 2.2 Sentence Adverbial 2.2.1 Features of Sentence Adverbials 2.2.2 Syntactic Realizations of Sentence Adverbials 2.2.3 Functions of Sentence Adverbials 2.2.3.1 Marking the Speaker' s Epistemic Stance 2.2.3.2 Expressing the Speaker's Attitude and Evaluation 2.2.3.3 Commenting on the Style or Manner of Speaking 2.3 Comment Clause 2.3.1 Features of Comment Clauses 2.3.2 Categories of Comment Clauses 2.3.3 Functions of Comment Clauses 2.3.3.1 Expressing the Speaker' s Doubt or Certainty 2.3.3.2 Expressing the Speaker' s Attitude and Evaluation 2.3.3.3 Conveying Comments on the Manner of Speaking 2.3.4 Non-clausal Sentence Adverbial and Comment Clause 2.4 Discourse Marker 2.4.1 Features of Discourse Markers 2.4.2 Categories of Discourse Markers 2.4.3 Functions of Discourse Markers 2.4.3.1 Textual Functions 2.4.3.2 Interpersonal Functions 2.5 Sentence Adverbial, Comment Clause and Discourse Marker 2.6 Discourse Markers and Grammaticalization 2.6.1 Introduction 2.6.2 Development of Discourse Markers 2.6.2.1 Semantic-pragmatic Changes 2.6.2.2 Syntactic Reanalysis 2.6.3 Are Discourse Markers an Example of Grammaticalization? 2.6.3.1 Features Typical of Grammaticalization 2.6.3.2 Principles of GrammaticalizationChapter 3 Actually: From a Phrase Adverbial to a Discourse Marker 3.1 Introduction 3.2 Phrase Adverbial 3.2.1 Emphasizer 3.2.2 Intensifier 3.3 Sentence Adverbial 3.3.1 Going beyond Conventionally Formed Expectations 3.3.2 Conflicting with Textually Based Expectations 3.4 Discourse Marker 3.4.1 Textual Functions 3.4.1.1 Marker of Contradiction 3.4.1.2 Marker of Elaboration 3.4.1.3 Marker of Topic Shift 3.4.2 Interpersonal Functions 3.4.2.1 Softening the Contradiction 3.4.2.2 Mitigating the Abruptness 3.5 Development of Actually 3.6 ConclusionChapter 4 (A) Kind of: From a Noun Phrase to a Discourse Marker 4.1 Introduction 4.2 A Kind of as a Noun-preposition Sequence 4.2.1 A Noun Phrase Meaning a Type of 4.2.2 A Nominal Premodifier Signaling Fuzziness 4.3 (A) Kind of as a Metalinguistic Hedge 4.3.1 Imprecision Signal 4.3.2 Special-style Signal 4.4 (A) Kind of as a Discourse Marker 4.4.1 Interpersonal Function 4.4.1.1 Mitigating the Assertive Force 4.4.1.2 Appealing to Common Ground 4.4.2 Textual Function 4.5 Variants of Kind of 4.6 Development of (a) Kind of 4.7 ConclusionChapter 5 The Thing is : A Discourse Marker Originating from a Matrix Clause 5.1 Introduction 5.2 Identifying the Relevant Item 5.2.1 Non-parenthetical the Thing is 5.2.2 Parenthetical the Thing is 5.2.3 Structurally Indeterminate the Thing is 5.3 Functions of Parenthetical the Thing is 5.3.1 Comment Clause Use 5.3.2 Discourse Marker Use 5.3.2.1 Marker of Justification 5.3.2.2 Marker of Contradiction 5.3.2.3 Marker of Topic Shift 5.3.2.4 Hesitation Filler 5.4 Thing is 5.5 Development of the Thing is 5.6 CnclusionChapter 6 You Know What: A Discourse Marker Originating from a Fullrogative 6.1 Introduction 6.2 Identifying the Relevant Item 6.2.1 Non-parenthetical You Know What 6.2.1.1 Proposition-deleted Interrogative 6.2.1.2 Deictic Use of You Know What 6.2.2 Parenthetical You Know What 6.3 Functions of Parenthetical You Know What 6.3.1 Comment Clause Use 6.3.2 Discourse Marker Use 6.3.2.1 Boundary Marker 6.3.2.2 Marker of Justification 6.3.2.3 Marker of Elaboration 6.3.2.4 Marker of Topic Shift 6.3.2.5 Hesitation Filler 6.4 Development of You Know What 6.4.1 Full Interrogative 6.4.2 Rhetorical Interrogative 6.4.3 Proposition-deleted Rhetorical Interrogative 6.4.4 Comment Clause 6.4.5 Discourse Marker 6.5 ConclusionChapter 7 Different Discourse Markers Used as Hesitation Fillers 7.1 Introduction 7.2 Differences between Different Discourse Markers 7.3 ConclusionChapter 8 Conclusion 8.1 Main Findings of This Study 8.2 Reformulation of the Related Dictionary Entries 8.2.1 Actually 8.2.2 (A) Kind of 8.2.3 The Thing is 8.2.4 You Know What 8.3 Influence of This Research on English Education in China 8.4 Directions of Further ResearchBibliography