(183）I can’t speak for everyone， but the format you work towards affects both your process and the work itself - I’ve tried working with a book in mind， and it doesn’t suit me， not at this point at least.
In Example (183)， the clause-final MSA at least shows its priority of information status.This MSA is the New in the part of rheme (cf.Fries， 2002： 125-126)， termed as N-Rheme.The MSA at least adds a force of explanation or afterthought to the attitude conveyed by the MV can’t.
By means of emphasis， the supplementary modal device is put between the subject and the core modal device， and the modal meaning is either total rejection or total agreement.Supplementary modal devices only strengthen or weaken the stance in this case.For example：
(184）…whereas the provision of such information undoubtedly would impose an obligation…
(185）…whereas implementation alone will reveal loopholes or weaknesses in the new collection system…
In Examples (184）and (185)， undoubtedly emphasizes would and alone emphasizes will.Both cases show the extremeness of modality.This situation is a little different from interpolation， in that in the former case the MSA concerned exhibits a preemptive tone over the attitude to be expressed later， whereas in the latter case no preemptive tone is put on and the discourse participants tend to regard the attitude or judgment expressed by the MSA as a further elaboration of that conveyed by the MV.The stance status is just reversed in the latter case.
By means of intensification， the supplementary modal device is put after the core one， and the modal meaning is addition or subtraction， such as：
(186）… it may just as well be the world as God.
(187）… people will sometimes tell you that…
In Examples (186）and (187)， just as well strengthens may in degree， and sometimes specifies will in usuality.Notice that there seems to be an overlap between interpolation and intensification.Maybe， interpolation could be taken as related to both syntactic positions and semantics whereas intensification deals with semantics only.Also， intensification normally refers to the semantic category of strengthening whereas interpolation has to do with more semantic categories including strengthening and weakening.However， this distinction is delicate and should be regarded as relative rather than absolute.
By means of focusing， the core modal device is repeated together with the supplementary one， and the stress in terms of pronunciation is placed on the core modal device.This situation normally occurs in spoken discourse.For example：
(188）You people must have faith； you must never be stampeded by rumors or guesses.
In Example (188)， the MV must is repeated together with the MSA never.Core modal devices repeated in this case strongly signal the speaker’s attitude or judgment； the MSAs involved further specify the stance involved for cognitive， pragmatic and evaluative motivations.
The pattern of word (or word group）+ clause is similar to thematization of the word (or word group）+ word (or word group）pattern.Yet， in the former case the supplementary modal device stands as comment， attitude， or judgment over the whole proposition that contains the core modality device， whereas in the latter case modality supplementing is mainly related to the core modal device.In Greenbaum (1969）and Quirk et al.(1985）such supplementary modal devices are termed as disjuncts.In Dik et al.(2005）they are referred to as interpersonal satellites (including proposition and illocutionary satellites).In Halliday & Matthiessen (2004）they are labeled as comment adjunct (specifically the speech-functional adjuncts).
Consider the following：
(189）Technically I can’t catch up until he drops the strip， or dies.
(190）Hopefully they’ll get around to doing the DC Archives Metamorpho sooner rather than later.
In Example (189)， the MSA technically adds a force of judgment to the proposition revealing the inability of acting (dynamic modality）conveyed by the MV can’t.In Example (190)， the MSA hopefully adds another force of inclination from the addresser to the inclination (conveyed by the MV will）of other people.
The pattern of clause + clause occurs within a clause complex.The Dutch Functional School (cf.Hengeveld， 2005： 26-34）advocates the idea that modal satellites can appear in different clauses， i.e.compound or coordinated clauses， and complex clauses (with one being the main clause， and the other being the dependent or subordinate clause).Consider the following：
(191）John must be home， because that certainly is his car outside.
(192）Maybe it’s certain that blindness can be cured.
In Example (191)， must is the core modal device， modified by the proposition of the subordinate clause that includes the MSA certainly.In Example (192)， the main clause contains an MV can， and the proposition concerned is modified by the MSA maybe.It should be noted here that MVs， or the clauses that contain MVs， have the privilege of acting as core modal devices whereas MSAs， or clauses that contain MSAs tend to function as supplementing modal devices.
According to SFL， the syntactic relationship between the main and subordinate clauses can be indicated by the symbols α x β (enhancement)， and α ^ β (projection)； that between the coordinated clauses by the symbols 1 = 2 (elaboration， paratactic）or α = β (elaboration， hypotactic)， and 1 + 2 (extension， paratactic）or α +β (extension， hypotactic).It is clear that the pattern of clause + clause as modality supplementing is more complex to analyze than the clause complexes or simplexes in SFL.It is not the main clause that will surely have the status of being the core modal device or of being the place where the core modal device appears.It may be the dependent clause which has the core modal device or where the core modal device shows up.