Common nouns [...] are precisely what their name implies, common to a class of referents; hence they are typically accompained by a Deictic and often other elements as well. They name classes of person, other living things, objects, collectives, and institutions; as well as, by grammatical metaphor, phenomena that would typically appear as adjectives (qualities) or as verbs (processes and relations). These metaphorical ʻthingsʼ often occur without further specification, since their referents cannot be said to have members in the usual sense.
- Halliday (1985), a pag.168