Chapter 3 indicates that MSAs can highlight such interpersonal meanings as value, stance and social distance.This chapter will give a classification of MSAs and demonstrate the functions of MSAs.Such an exploration will lay a foundation for the discovery of the lexicogrammatical realization of interpersonal meanings by MSAs, and the discussion of the empirical studies on MSAs.
It is assumed that MSAs can be classified into six types, namely, limitation, probability & usuality, confidence, clarification, evidence and reasoning.MSAs can perform three functions in combination with MVs, i.e.disambiguation of modal vagueness, modal synergy and prominence of generic features.
4.1 Classification of MSAs
It must be understood that MSAs are related to the needs at the clause and discourse levels.The parasitic relationships between MVs and MSAs play an important part in this sense.Based on the parasitic relationships between MSAs and MVs at the clause and discourse levels as well as the needs of rhetorical structure in discourse, MSAs are postulated to involve six types in functions, namely, (a）limitation; (b）probability & usuality; (c）confidence; (d）clarification; (e）evidence; (f）reasoning.
4.1.1 Parasitic relationships at the clause level
Heltoft (2005: 90）argues that MVs are classified into three types: inherent, objective and subjective, in terms of their positions in the layered system of clause.Heltoft’s argument can be indicated as follows in Table 4.1.
Table 4.1 indicates that MVs are layered at the clause level.Sometimes the layer is objective and concerns reality; at other times the layer is subjective and concerns illocution.The subjective, objective and inherent MVs have two layers of modality each (5th and 6th layers; 4th and 3rd layers; 2nd and 1st layers).As is known from SFL (Halliday, 1994; Halliday & Matthiessen, 2004), MVs and MAs can function equally at the clause level in some situations.Hence, it is reasonable to assume that MAs as objective means of modality can co-occur with MVs as subjective means of modality.In this way, modal synergy is displayed.As a result, structurally and semantically modality supplementing through MSAs appears at the clause level.
Affected by the core modal devices-MVs, MSAs are generally placed in seven positions at the clause level.These positions are listed as follows (cf.Quirk et al., 1985: 490-491; Hoye, 1997: 148):
a.I (initial）Possibly they may have been sent to London.
b.iM (initial-medial）They possibly may have been sent to London.
c.M (medial）They may possibly have been sent to London.
d.mM (medial-medial）They may have possibly been sent to London.
e.eM (end-medial）They may have been possibly sent to London.
f.iE (initial-end）They may have been sent possibly to London.
g.E (end）They may have been sent to London possibly.
The positions and mobility of MSAs stem from their parasitic reliance on MVs.As the examples show, the clausal mobility of possibly generates potentially significant shifts in terms of what it focuses on.For instance, the I and E positions are normally associated with comment adjuncts.The I position has a theme-setting role and helps to topicalize the modality related to the proposition.The E position usually occurs in spoken rather than written discourse, where it occurs almost as an afterthought and has the effect of strengthening or weakening what has been said before.In comparison, the M position is normally linked to mood adjuncts.One of the clausal roles of epistemic adverbs is to emphasize the modality conveyed by MVs, and for that reason mood adjuncts may either be placed after MVs (M）or precede MVs (iM).Consider the following:
(118）The result easily could be a big minus, indicating that you’re spending or planning to spend more than your projected income.[iM]
(119）He invents an occasion on which the glasses may very easily have been lost or stolen.[M]
In Example (118), the MSA easily is used in the iM position as a means of emphasizing the attitude denoted by the MV could.In Example (119), the MSA very easily is used in the M position, emphasizing the attitude denoted by the MV may in a slightly different way.Therefore, the parasitic relationship between MSAs and MVs can affect the positions or distributions of the former with the latter as objects of reference.Van Valin (2005: 196-197）proposes two concepts of subordination: daughter subordination and peripheral subordination (the former for inter-clausal relation, and the latter for intra-clausal relation).The parasitic relationship between MSAs and MVs at the clause level can be described as mostly peripheral subordination.As van Valin (ibid）shows, there is generally a syntax-semantics interface in English.Hence, the interpersonal functions of MSAs cannot be separated from their clausal positions.
As a result, MSAs at the clausal level stem from two sources: clause-oriented and predication- oriented.Clause-oriented MSAs are those resulting from the effects of the clause as a whole.This situation shows that the MSAs are further comments on the propositions, or further indicate speech acts (i.e.disjuncts).In this sense, they are additional means of conveying attitudes or judgments based on the existing MVs.Predication-oriented MSAs (including some adjuncts as well as MAs）are those resulting from the effects of the MVs.They do not express comments on the propositions, nor do they further indicate speech acts.In this sense, they are different additional means of attitudes or judgments.MSAs can be classified at the clause level as in Table 4.2.