All the adjectives are traditionally divided into two large subclasses: qualitative and relative. Relative adjectives express such properties of a substance as are determined by the direct relation of the substance to some other substance. Qualitative adjectives, as different from relative ones, denote various qualities of substances which admit of a quantitative estimation, i.e. of establishing their correlative quantitative measure.
Prof. Blokh suggests that distinction be based on the evaluative function of adjectives. According as they actually give some qualitative evaluation to the substance referent or only point out its corresponding native property, all the adjective functions may be grammatically divided into "evaluative" and "specificative". One and the same adjective, irrespective of its being "relative" or "qualitative", can be used either in the evaluative function or in the specificative function.
From a syntactic point of view, adjectives can be divided into three groups:
1) adjectives which can be used attributively and predicatively (a healthy man – the man is healthy);
2) adjectives which can be used attributively only (a complete idiot – *the idiot is complete);
3) adjectives which can be used predicatively only (*a loath man – the man is loath to agree with it).