The Three Types Of Element

Halliday & Matthiessen (1999: 99, 101):

There are three types of semantic elements serving in figures — processes, participants and circumstances. Broadly speaking, these are constructed in the grammar as follows.

(i) Within the ideational component: they are realised by different classes of units:

process ➘ verbal group

participant ➘ nominal group

circumstance ➘ adverbial group, prepositional phrase

Participants tend to be inherent elements of a figure; circumstances are typically optional.

(ii) Relating to the interpersonal metafunction: participants can serve as Subject; circumstances and processes cannot. Furthermore, participants and circumstances can serve as WH-elements, but processes cannot (if the process is being questioned, a participant element has to be construed as a Range: what...do?)

(iii) Relating to the textual metafunction: participants and circumstances can both readily serve as Theme (though their potentials differ); processes only rarely, other than in imperative clauses. Participants and (more restrictedly) circumstances can serve as referables identified by referring expressions, but processes cannot — as with WH-interrogation, they have to be construed as a Range together with the pro-verb do as Process: do it/that (see Halliday & Hasan, 1976: 125).

These properties are summarised in Table 2(11).