How Many Topical Themes Per Clause?

In 1925	Halliday	was	born
Theme: marked	Rheme
Location	Goal	Process: material
circumstantial Adjunct	Subject	Finite	Predicator

Halliday & Matthiessen (2014: 91, 105, 107):

As a general guide to start off with, we shall say that the Theme of a clause is [realised by] the first group or phrase that has some function in the experiential structure of the clause, i.e. that functions as a participant, a circumstance or the process. …

The guiding principle of thematic structure is this: the Theme contains one, and only one, of these experiential elements. This means that the Theme of a clause ends with the first constituent that is either participant, circumstance or process. We refer to this constituent, in its textual function, as the topical Theme. 

There may however be other elements in the clause preceding the topical Theme. These are elements that are either textual or interpersonal in function, playing no part in the experiential meaning of the clause.

Beware of those who do not understand the distinction between the highlighting of a functional element (Theme) and functional element that is highlighted (e.g. Subject, Senser, etc.).

Theme Vs Information

Where did you put it?

I	put	it	in the cupboard
Theme	Rheme
Given			New

Who put this in the cupboard?

I	did
Theme	Rheme
New: marked

Halliday & Matthiessen (2014: 120):

But although they are related, Given + New and Theme + Rheme are not the same thing. The Theme is what I, the speaker, choose to take as my point of departure. The Given is what you, the listener, already know about or have accessible to you. Theme + Rheme is speaker-oriented, while Given + New is listener-oriented. 

But both are, of course, speaker-selected. It is the speaker who assigns both structures, mapping one on to the other to give a composite texture to the discourse and thereby relate it to its environment.

Revealing The ‘Slow Reveal'

1. Something moved inside.
2. Two dark eyes stared out at him.
3. He snatched a frightened glimpse of a man’s face. Staring. Watching….

1. The first clause construes a happening, but the Thing realising the Medium of the Process is not differentiated for [± conscious], let alone [± human].

Something	moved	inside
Actor	Process: material	Location: relative: rest

2. The second clause construes a conscious process as a behaviour, thereby assigning [+conscious] to the Medium of the Process, but not resolving the question of [± human]. This ambiguity is reinforced by the use of synecdoche — realising the Behaver in terms of its parts (two dark eyes) — and by the lexical choice of dark, which potentially signals both the unknown, and a negative assessment ('sinister') of the conscious Behaver.

Two dark eyes	stared	out	at him
Behaver	Process: behavioural	Location: relative: motion: away from	Location: orientation
marked focus of New

The potential threat of a 'dark' consciousness is then supported the lexical choice of Process, stare, which also provides the Quality of the Process ('look fixedly'), and grammatically by the 'emanating' directionality given to the Process by the 'motion' and 'orientation' Locations.

3. The third clause metaphorically construes a 'middle' mental clause as an 'effective' material clause.

Senser	Process:		Manner: quality	mental: perception	Phenomenon
He	snatched	a	frightened	glimpse of	a man’s face
Actor	Process: material	Goal
					focus of New

Because the wording of a metaphorical clause additionally realises the meaning of its congruent agnate, this simultaneously construes both the outer (material) experience and the inner (mental) experience of the protagonist.

Less abstractly, in terms of outer experience, the clause construes the protagonist as taking quick action — with the lexical choice of Process, snatch, also providing the Quality of the Process ('quickly seize'). On the face of it, this is self-directed action in response to the potential threat implied in the second clause.

Only more abstractly does the clause construe the inner experience of the protagonist: as perceiving a Phenomenon — now confirmed as apparently [+ human], through synecdoche (a man's face) — in an emotional manner (frightened).

The final two behavioural clauses put the information Focus on processes, but nevertheless keep material action frozen, by first repeating the potential threat staring ('look fixedly'), but then reducing the threat through the lexical choice of watching.

Staring

Process: behavioural

focus of New

Watching

Process: behavioural

focus of New