Thompson (2014: 110-1):
It is useful to compare an existential process with a possible rewording using the verb ‘exist’:
Maybe some other darker pattern exists.
Although this is very close in meaning, the verb ‘exist’ itself is best analysed as a material process: the rewording reflects at least partly a choice to represent the entity (‘pattern’) as involved in a ‘going-on’ (which happens to be that of existing). The analyses of the two clauses are given in Figure 5.20 for comparison (‘Maybe’ is, of course, left unlabelled since it has no experiential meaning).
Blogger Comments:
To be clear, such clauses are existential, not material, on several criteria.
- They satisfy the category meaning of existentials 'being (existence)', but not of materials 'doing (doing, happening, doing to/with)'.
- There is no pro-verb, as there is for materials ('do, do to/with').
- The unmarked present tense is the simple present ('exists') of existentials, not the present in present ('is existing') of materials.
See Halliday & Matthiessen (2014: 354) for criteria distinguishing process types.
