2 Metadiscourse
The concept of metadiscourse was first proposed by Zelling Harris in 1959. He proposes that metadiscourse is a way to understand language and represents a writer to lead the readers through the perception of a text. Later, metadiscourse has attracted many scholars’ attention, and the studies on metadiscourse have increased in recent years. Due to various research perspectives, metadiscourse has been labeled differently, such as signaling (Meyer, 1975), non-topical linguistic material (Lautamatti, 1978), gambits (Keller, 1979), meta-talk (Schriffrin, 1980) and discourse about discourse (Williams, 1981).

2.1 Definition and Issues
The definition of metadiscourse has undergone different interpretations. Various scholars put forward their own point of view. Meyer (1975) defines metadiscourse as a ‘signaling’ and states writing is certain aspects of semantic content and the structural organization of the content. Williams (1981) labels metadiscourse as a stylistic variable and it is a very important part in writing. Crismore (1984) points out that metadiscourse can be defined narrowly depending on what field scholars are working in: speech communication, rhetoric and linguistic. Luhmann (1987) considers metadiscourse as a sign. The concept of metadiscourse is based on a view of writing and speaking as a social communicative engagement, and it offers the way of understanding that we project ourselves into the texts.

Later, many scholars, such as Crismore (1989), Markkanen and Steffensen (1993), make studies in this field based on William’s research. They have reached the same conclusion that metadiscourse is to help readers connect, organize, interpret, evaluate and develop attitudes toward materials. Furthermore, they make a clear distinction between metadiscourse and propositional content, and they regard propositional content as the primary level.

Hyland (2000) defines metadiscourse as an umbrella term which is used to include cohesive and interpersonal features which help relate a text to its context. Metadiscourse is often defined as “discourse about discourse” which stresses on the text itself. Nash (1992:100) considers that the usage of metadiscourse suggests boundaries of definition no more firmly drawn than those of rhetoric or style. One reader may perceive a clear stylistic intention in something which another reader dismisses as a commonplace.

In the process of communication, writers intend to better reclaim their intention to the readers. It is not only to pass the information to each other, but also to select the appropriate component to organize discourse and express their own attitudes and perspectives effectively. Largely, the latter influences the acceptance and understanding of readers.
2.2 Classification of Metadiscourse
Various classifications of metadiscourse have been proposed due to different viewpoints since 1981. Almost all the classifications of metadiscourse are attempted in the light of Halliday’s theory of meta-functions of language.

According to Meyer’s (1975) view, metadiscourse is labelled as signaling. It shows writer’s perspective on the content which is covered in the primary discourse. Meyer also identifies four major types of signaling, such as the signaling specifying the structure of relations in the content structure, the signaling revealing information, the signaling summarizing statements and pointer words.

The same as Meyer (1975), Lautamatti (1978) considers metadiscourse as an aspect of non-topical linguistic material. She classifies two levels of linguistic material in written discourse: the topical material and the non-topical material which is metadiscourse. She finds that non-topical material forms a framework for the topical material which allows readers to relate the discourse to a larger framework of knowledge and helps to understand the internal organization of the discourse. She recognizes five types of non-topical material: discourse markers, illocution markers, modality markers, attitude markers and commentary markers. 《傲慢与偏见》小说与电视剧的元话语运用比较(3):http://www.751com.cn/yingyu/lunwen_7971.html