Previous studies show that MVs and MAs possess different kinds of modal meaning.Larreya (2003: 40）indicates that MVs express unreality which can be absolute or relative, and direct or indirect.Palmer (2003: 7）shows that MVs express three types of modal meaning: epistemic, deontic and dynamic.SFL distinguishes modalization (equivalent to epistemic）from modulation (equivalent to deontic）modality.Perkins (1983: 89）mentions that all MAs primarily express epistemic modality; it implies that a small number of MAs express deontic and dynamic modality.
It is held that the modal meanings of MSAs could be similar to those of MVs.However, it should be noted that some MSAs are indeterminate in modal categories, such as those functioning as comment adjuncts (e.g.politically and contextually), which are absent in discussing the modal meanings of MAs.Therefore, it is suggested that the modal meanings of MSAs be divided into three types: (a）modulation (including dynamic); (b）modalization; (c）indeterminacy.
The occurrences of MSAs in modal categories in the four genres can be listed in Figure 6.2.
Notice that Types 1, 2 and 3 refer to modulation, modalization and indeterminacy respectively.
The findings can be described in the following way:
A.The modulation of MSAs in the four genres can be listed as below in a descending order: LR (72%）> PS (40%）> JI (32%）> AW (17%）(LR has the biggest percentage of Type 1 MSAs whereas AW the smallest one).
B.The modalization of MSAs in the four genres is just opposite: AW (58%）> JI (50%）> PS (46%）> LR (7%).
C.Type 3 MSAs (i.e.those MSAs that are indeterminate in modal categories, which have to be inferred through the MVs they co-occur with）appear most often in AW and least in PS: AW (25%）> LR (21%）> JI (18%）> PS (14%).
Figure 6.2 Occurrences of MSAs in modal categories in four genres
The findings are significant for revealing the interpersonal meanings of stance and social distance involved in the four genres.
LR is obligatory in generic nature, and accordingly modulation MSAs occur most frequently (72%).These MSAs strengthen the stance of obligations conveyed by the MVs they co-occur with, and in this way another interpersonal meaning, i.e.hierarchy, is highlighted.
In contrast, AW is a typical genre that follows the practice of politeness, negotiation and tentativeness.Thus, modalization MSAs appear most frequently in this genre (58%).In this way, modalization MSAs help academic writers to negotiate with others, and make a balance between deference and solidarity.It is not assumed that hierarchy is highlighted in AW by means of modalization MSAs.
The indeterminate MSAs occur most often in AW (25%).They mainly function as comment adjuncts in this genre.It is postulated that writers use these MSAs to comment on or evaluate others’ or their own ideas.Therefore, these MSAs can be a means of negotiating with others or tentatively putting forward ideas in AW.
LR targets at objective aspects more than subjective ones, and hence the percentage of indeterminate MSAs in this genre is high (21%).The indeterminate MSAs are related to such concepts as clarification, evidence, confidence and reasoning.In LR, it is found that evidence and reasoning are highlighted in indeterminate MSAs.This shows the cognition involved of the law-makers, who intend to give a precise and exact idea about the obligatory nature of law.
It could be found that the occurrences of MSAs based on modal categories are interrelated with generic differences.These distribution differences largely result from the impacts of the contextual factors as explored in Chapter 3.
An examination of the corpora can be helpful in better understanding the occurrences of MSAs based on modal categories.Consider the following:
(271）You may be called upon to justify the amount of time you have spent on the Internet or the sites you have visited, so always bear this in mind when surfing the net.
(272）If you can average 7 miles (11 kilometers）a week, including a 3 mile (4 1/2 kilometer）walk once a week, you will increase the strength not only of your legs and back but possibly also of your arms, as walking may benefit even bones that are not directly involved.
(273）In many cases, for longer e-mails it may be better to prepare the message offline and check it carefully before dispatch.
Example (271）is taken from LR.The MV may is about modulation rather than modalization, and the MSA always, which is about modalization, indicates obligation (high-valued）more than probability, though.
Example (272）is an extract from an essay of natural sciences in AW.There are two MSAs in this example, i.e.possibly and even.Possibly is related to probability (low-valued), and even reasoning.The MVs in Example (272）are all related to modalization, namely, can (low-valued), will (median-valued), and may (low-valued).Thus, possibly (modalization）and even (indeterminate MSA, here serving the function of modalization）supplement the modalization conveyed by the three MVs, i.e.can, will and may.
Example (273）is taken from LR.In many cases is an indeterminate MSA providing evidence, making the obligation conveyed the MV may objective and institutional.
Seen in this way, the MSAs of different types of modal category vary in interpersonal meanings from genre to genre.In many situations, there is a generic expectation involved.
6.9 Genre-affected pattern-like MSAs
Lorenz (2002: 317-326）classifies adverbs into three types according to their discourse functions, namely, comparative, evaluative and modal adverbs.It is believed that MSAs may be classified in a similar way.Table 6.8 shows such a classification.