Halliday & Matthiessen (1999: 270):
Another type that is also not specifically associated with learned discourse — with the registers of educational knowledge — is that of be/go + minor process => process: for example:
her speech covered five points ('was about')the road skirts the lake ('goes alongside')shall I accompany you? ('go with')this replaces the one you had before ('is instead of)who does she resemble most? ('is like')
These are not in the language of a pre-school child; they are learnt as the written language of the primary school, intermediate between the commonsense language of daily life in the home and the technicalised educational discourse of the secondary school.