All Modalities Are Realised As Indicative

Halliday (1994: 356, 357):

Modality Type: Modalisation vs Modulation

Halliday (1994: 356, 357):

Embedded Projections

Halliday (1994: 271):

Quotes, Reports And Facts As Meanings And Wordings

Halliday (1994: 269, 270):

The Four Sub-Classes Of Fact Noun

Halliday (1994: 266-7):

Types Of Projection

Halliday (1994: 264):

Nouns Of Projection

Halliday (1994: 263-4):

Free Indirect Speech

Halliday (1994: 261-2):

Projection Of Propositions And Proposals Summarised

Halliday (1994: 260):

Reporting vs Quoting Verbs

Halliday (1994: 255:

Verbally Projected Clauses

Halliday (1994: 141):

Modulated Clauses: Proposals vs Propositions

Halliday (1994: 89):

Modalisation

Halliday (1994: 89):

Modality

 Halliday (1994: 88):

The Semantic Function Of The Mood Element

Halliday (1994: 77-8):

The Grammar Of Propositions vs Proposals

Halliday (1994: 70-1):

Proposition vs Proposal

Halliday (1994: 70, 71):

Modalisation

Halliday & Matthiessen (1999: 526):

The former [deriving from the polarity of propositions] are along the dimensions of "probability" and "usuality", the first being the more elaborated of the two (because more arguable); for example,

That was a snake.

— It wasn't. It can't possibly have been a snake.

— Couldn't it? Don't you think so? I think it might have been.

— It probably wasn't. But snakes can appear round here.

All of these represent probability except the final can which means 'sometimes' (usuality). Note that it is always the judgment of speaker or listener that is represented as a choice of modality, not that of any third party (this is one of the boundaries drawn between 'me-&-you' and 'the rest').

The Space Between Positive And Negative Polarity

Halliday & Matthiessen (1999: 526):

Languages differ considerably in their construction of this space, and in the extent to which they interpret it grammatically. In English, there are four distinct grammatical traverses between 'yes' and 'no', two deriving from the polarity of propositions ('it is/ it isn't') and two from the polarity of proposals ('do! / don't!').

Interpersonal Semantics: Move

Halliday & Matthiessen (1999: 376-7):

The interaction base provides the resources for enacting social roles and relations as meaning, (prototypically) in dialogue. The interaction base includes the strategies for adopting and assigning speech roles, for giving and demanding assessments, and the like. The locus of these strategies is a unit of interaction or move. A move is typically mapped onto a figure from the ideation base: a speaker construes a quantum of experience as a figure and enacts this figure as a move in dialogue, either as a proposition or as a proposal. This mapping between figure and move is a central feature of the way we jointly construct and negotiate experience.