We have stressed at various points that a linguistic description is a statement of what the speaker can mean; and that ʻmeaningʼ, in its most general sense, includes both function within one level and realization of elements of a higher level. These ʻhigher levelʼ elements will, at one point, lie outside the confines of what we recognize as language.
- Halliday (1973), a pag.79

Meanings are expressed through grammatical patterns; but meanings are themselves the expression, or realization, of options in behaviour, and some of these options have a broad socio-cultural significance.
- Halliday (1973), a pag.8