Among the words signifying properties of a noun there is a lexemic set which claims to be recognised as a separate part of speech as different from the adjectives (the words built up by the prefix a- and denoting different states, mostly of temporary duration: afraid, agog, adrift, ablaze).
In traditional grammar these words were generally considered under the heading of predicative adjectives.
Notional words signifying states and specifically used as predicatives were first identified as a separate part of speech in the Russian language by L. V. Shcherba and V. V. Vinogradov. The two scholars called the newly identified part of speech the category of state (and, correspondingly, words of the category of state: тепло, зябко, одиноко, радостно, жаль, лень, etc.). Traditionally the Russian words of the category of state were considered to belong to the class of adverbs, and they are still considered as such by many Russian scholars.
On the analogy of the Russian category of state, the English qualifying a-words were given the part-of-speech heading category of state (B. A. Ilyish) and the term used for words constituting this category was later changed into stative words/statives.
The part-of-speech interpretation of the statives is not shared by all linguists working in the domain of English. Usual arguments given pro separating them into a part of speech are as follows (B. S. Khaimovich and B. I. Rogovskaya: 1) the statives (ad-links) are opposed to adjectives on a purely semantic basis (adjectives denote qualities, and statives-adlinks denote states); 2) statives-adlinks are characterised by the specific prefix a-; 3) they do not possess the category of the degrees of comparison; 4) they are not used in the pre-positional attributive function,
This view of the stative was not supported by any special analysis and formed on the grounds of mere surface analogies and outer correlations. The later semantic and functional study of statives (their inner properties, historical productivity, systemic description) showed that statives, though forming a unified set of words, do not constitute a separate lexemic class existing in language on exactly the same footing as the noun, the verb, the adjective, the adverb. It should be looked upon as a subclass within the general class of adjectives since statives are not directly opposed to the notional parts of speech taken together, but are quite particularly opposed to the rest of adjectives.
Therefore the general subcategorisation of the class of adjectives is effected on the two levels:
1) on the upper level the class is divided into the subclass of stative adjectives and common adjectives;
2) on the lower level the common adjectives fall into qualitative and relative.