Halliday & Matthiessen (1999: 98, 100):
There are four types of figure — doing & happening, sensing, saying, being & having. Broadly speaking, these are constructed in the grammar as follows:(i) Within the ideational metafunction, each is realised congruently by one particular transitivity type: doing & happening ➘ material, sensing ➘ mental, saying ➘ verbal, and being & having ➘ relational. These have various reactances, such as the number and nature of participants and the unmarked present tense selection (see Table 2(10)).(ii) Relating to the interpersonal metafunction: in any given register there may be typical correspondences between the type of figure and the speech function; e.g. in procedural registers, material clauses are typically imperative, relational ones indicative.(iii) Relating to the textual metafunction: different types of figure are presumed in different ways and have different potential for textual prominence; e.g. only material clauses are substituted by the pro-verb do (to/with).
Blogger Comments:
With regard to Table 2(10), the Medium of an identifying clause is the Identified, which coincides with the Value only when the relation is encoding. In decoding clauses, it is the Token that is the Medium/Identified.