A number of studies have been carried out on the use of DMs, such as those by Müller (2004), Fung and Carter (2007), Aijmer (2002), Hellermann and Vergun (2007), and Zhao, (2013). Müller for example, investigated the use of ‘well’ by German EFL speakers, and compared this to its use by American NS. The findings of the study demonstrated that in nine functions out of twelve, EFL learners used ‘well’ more than NS. Müller (2004) explained that the, “German speakers on average used well more than the Americans did in all functions except for three: to correct a phrase, to quote, and to introduce the speaker’s own opinion” (p. 1179). This result contrasted with the outcomes for the use of ‘so’ in the study. These findings are interesting because they differ from those of other studies, most of which have found that the use of DMs tends to be more frequent in NS speech than in non-native discourse, although Müller’s study was limited
to the use of two DMs: well and so.
Müller (2004) explained the factors affecting the use of DMs by German EFL speakers as follows: i) the DMs ‘well’ and ‘so’ occur frequently in German textbooks of English; ii) there is an “overuse of well in an attempt to avoid the German-sounding so” (p. 1157), and iii) “The frequency of translational equivalents for well in German discourse could be another influence on well’s frequency in the German speakers’ data” (p. 1180).
Another influential comparative study was carried out by Fung and Carter (2007) which examined the production and use of DMs by NS and NNS. They defined DMs as “intra- sentential and supra-sentential linguistic units” (p. 411). DMs in their study functioned the same way as in many previous studies. That is, they had no propositional or connective function in utterances. However, they had a vital function as they signalled changes in the development of the participants’ discussion rather than fulfilling connective or propositional purposes (Fung & Carter, 2007). Fung and Carter proposed a multi-categorical model comprising four categories, each of which described a function: interpersonal, referential, structural, and cognitive. They then specified five general characteristics of DMs under the headings: “position”, “prosody”, “multi- grammaticality”, “indexicality” and “optionality” (cf. 2.5), stating that these characteristics apply to linguistic expressions.
Fung and Carter used two different corpora: CANCODE, and recorded conversations of secondary students in Hong Kong. Using their findings, they argued that DMs function as “useful contextual coordinates” (2007, p. 435) in pedagogical settings for both native and NNS to structure and manage speech. In addition, they have a “fundamental role in spoken interaction” (Fung & Carter, 2007, p. 410). This research can be described as
comprehensive for two reasons: first, it gave clear and simplified functional categories covering a range of DMs, in contrast to the limited focus of Schiffrin’s (1987) study; second, it provided a clear description of the characteristics of DMs (see section 2.5).
A significant in-depth study conducted by Aijmer (2002) provided a descriptive framework for DMs, employing the term “discourse particles” (p.1). She argued that “if a particle expresses anything at all, it must be a procedural meaning” (Aijmer, 2002, p. 16), which echoes many researchers who have asserted that DMs have no propositional meaning. Aijmer (2002) proposed two “macro levels”: “textual” and “interpersonal” on which discourse particles can be analysed (p. 13). She claimed that DMs have functions in discourse on both an interpersonal level (attitudes and participants) and a textual level (text), and that these are context specific. In this way, Aijmer’s (2002) findings were similar to those of Fung and Carter (2007), and demonstrated that the same DM has different uses, which are dependent on the speaker’s thoughts and attitudes, and the particular context.
Hellermann and Vergun (2007) concentrated on three specific interpersonal DMs: well, you know, and I mean, investigating their use and function by beginner adult EFL learners who were not taught explicitly. They found various functions of these DMs in the discourse, such as the use of like. Then, they divided the functions for the use of like in their study into three categories: “focus”, “loose interpretation/approximation”, and “exemplifier” (p. 169). The results revealed that the adult learners used DMs less frequently than NS, in line with the findings of previous research. In addition, Hellermann and Vergun (2007) argued that, “while teachers need not spend significant parts of their class time teaching these DMs, there is a need to make learners aware of these markers and their pragmatic functions” (p. 177). They also believed that English language teachers
should use examples from natural everyday conversations between NS to highlight the proper use of these markers and explain the reason why they do not occur in some settings. In addition, they stated that raising learners’ awareness and providing opportunities for practice within the classroom would help learners access these markers in appropriate situations outside the classroom, aiding linguistic transition into US culture (Hellermann & Vergun, 2007).
A recent comparative study by Zhao (2013) examined differences in the use of DMs in speech by Chinese EFL learners, and explored “the relationship between English proficiency and the pragmatic fossilization of DMs” (p. 707), comparing this to DM use by NS. The results of the study demonstrate that the pragmatic fossilization of DMs occurs because language learners fail to grasp their pragmatic functions. In addition, the study identified a lack of awareness in the Chinese learners of the significance of using these markers in building textual coherence. Thus, Zhao (2013) argued that DMs should be taught using both explicit and implicit instruction within the classroom. He also argued, with regard to relevance theory, textual coherence of DMs should be provided through explicit instruction. In addition, he suggested that “teachers should provide learners with accurate and appropriate second language (L2) input and as many chances as possible to make enough L2 output in proper situation” (p. 707). Moreover, using the “relevance theoretical framework to instruct the teaching of DMs helps learners acquire the pragmatic function of DMs effectively” (Zhao, 2013, p. 707). In addition, Zhao (2013) noted that, DMs helped the speaker in organizing the ideas, producing explicit utterances and finally lead the hearer towards intentional interpretation.