h.Elaboration
i.Restatement
j.Condition
k.Circumstance
l.Cause
m.Concession
n.Background
o.Thesis-antithesis
Mann & Thompson’s model of relational propositions is helpful for the classification of MSAs.Specifically, this model indicates that discourse organization is based on the needs of the discourse and actual worlds.Chapter 3 mentions the cognitive, pragmatic and functional perspec- tives that exert impacts on the use of MSAs as a means of modality supplementing in discourse.These perspectives stress the crucial position of generic needs for the use of MSAs.As a means of conveying further attitudes or judgments in relation to MVs, MSAs should be related to discursive rhetorical structure as a whole, as proposed by Mann & Thompson (ibid).
4.1.4 Types of MSAs
Generally speaking, MSAs can be classified into six types based on the three criteria, i.e.the parasitic relationships at the clausal level, the parasitic relationships at the discourse level, and discursive rhetorical structure:
a.limitation (e.g.only, just and simply)
b.probability & usuality (e.g.probably, perhaps, always and never)
c.confidence (e.g.certainly, of course, surely, really and actually)
d.clarification (e.g.still, at least, particularly, in fact and indeed)
e.evidence (e.g.politically, culturally, in practice, and on a de facto basis)
f.reasoning (e.g.therefore, also, so to speak, even and ever)
Collins COBUILD English Language Dictionary (1987）gives detailed explanations of the meanings of some of these adverbs:
a.just is used for a past, present or future event that is referred to in talking; just can limit the importance, attractiveness or difficulty of something; just can be a means of politeness; just can indicate preciseness or exactness.
b.only indicates the relevant things; only limits the importance, attractiveness or difficulty of something; only can emphasize the triviality of something; only can denote the things that have to be done; only can demonstrate a wish or hope.
c.maybe indicates “uncertainty”, “suggestion”, “tentative explanation”, “guess”, and “hesitancy”.
d.hereinafter conveys “avoidance of complete salutation” or “brevity of salutation” (especially in legal documents).
e.on a de facto basis shows “actuality of power exercising”.
These dictionary explanations provide a hint about the modal senses of the mentioned adverbs functioning as MSAs.For instance, given the nature of power difference or social distance between law-makers and common citizens, it is not hard to know why on a de facto basis is somehow unique in LR.Similarly, the tentativeness of opinion-presenting in AW makes so to speak common on some occasions.It is justified to say that there is a generic expectancy for the occurrences of MSAs in different genres.Considering that MVs reflect the demands of genres, it can be safely concluded that accordingly MSAs supplement the attitudes or judgments expressed by MVs in relation to generic demands.
4.2 Functions of MSAs
Based on the contextual factors that exert impacts on the use of MSAs, namely, cognition, pragmatics, genre and evaluation, MSAs can perform three major functions, i.e.disambiguation of modal vagueness, modal synergy, and prominence of generic features.The following part will deal with these issues.
4.2.1 Disambiguation of modal vagueness
Lyons (1977: 797）points out that an utterance like Alfred may be unmarried is ambiguous.
The MV may in this example is either subjective or objective.In the former case, the speaker qualifies the possibility of Alfred’s being unmarried in terms of his own uncertainty.In the latter case, the possibility is presented as an objective fact, for example, if the speaker knows that 30% people of the group to which Alfred belongs are unmarried.In order to account for this distinction, Lyons claims that utterances have the general structure of the following, which is a layered structure:
I-say-so [It is so [ [Propositional Content]]]
(“neustic”）(“tropic”）(“phrastic”)
The “neustic” operator concerns the speech act, while the “tropic” indicates the degree of the speaker’s commitment towards the Propositional Content (“phrastic”).“In this format subjective epistemic modality can be accounted for in terms of the speaker’s qualification of the I-say-so component of his utterance.Objective modalized utterances can be described as having an unqualified I-say-so component, but an it-is-so component that is qualified with respect to a certain degree of probability, which, if quantifiable, ranges between 1 and 0.” (Lyons, 1977: 800）According to this structure or model, whether may is regarded as objective or subjective depends on the hearer’s or reader’s decoding mechanism.This is vague enough to justify the use of modality.In fact, sometimes it is difficult to distinguish subjective from objective modality, and even more difficult to discriminate between objective and completely objective modality.To work out the dilemma, MSAs are necessary in order to make the modal meanings concerned complete.
The use of MSAs is motivated by a number of factors.The functions of modality supplementing that MSAs perform partly lie in the disambiguation of modal vagueness in such areas as value adaptation, balance between modal implicitness and explicitness, balance between modal subjectivity and objectivity, and balance between modalization and modulation.
4.2.1.1 Value adaptation
Value is the certainty of delivering attitudes or judgments.In SFL, MVs and MAs can be measured by the scale of high, median and low.However, other adverbs that can serve modal functions, i.e.modal adjuncts, are classified differently.For instance, the values of mood adjuncts of intensity are classified as described in Table 4.3.