1. Diagnostic: Reversibility
Halliday & Matthiessen (2004: 215):
The ‘identifying’ ones are reversible … The ‘attributive’ ones are not reversible …
Halliday & Matthiessen (2004: 220):
The [‘attributive’] clauses are not reversible: there are no ‘receptive’ forms …
Halliday & Matthiessen (2004: 228):
These [‘identifying’] clauses are reversible. All verbs except the neutral be and the phased become, remain (and those with following prepositions like as in act as) have passive forms … Clauses with be reverse without change in the form of the verb and without marking the non-Subject participant …
2. Diagnostic: Definiteness
Halliday & Matthiessen (2004: 219):
The nominal group functioning as Attribute construes a class of thing and is typically indefinite: it has either an adjective or a common noun as Head and, if appropriate, an indefinite article … It cannot be a proper noun or a pronoun since these do not construe classes.
Halliday & Matthiessen (2004: 228):
The nominal group realising the function of Identifier is typically definite: it has a common noun as Head, with the or other specific determiner as Deictic, or else a proper noun or pronoun. The only form with adjective as head is the superlative ….
