The category of correlation
The category of correlation is expressed by the opposition of perfect-non-perfect forms. The position of the perfect forms in the system of the English verb is a problem which has given rise to a lot of contradicting theories. In the first half of the century the perfect was treated as a peculiar tense category. For example, Otto Jespersen, H.Sweet, Curme and some other linguists consider that the perfect should be classed in the same list as the present and past.
The similar view is expressed in the book "English Grammar" by Ganshina and Vasilevskaya published in 1953. Other linguists treated the perfect as an aspect category. This view was held by a number of grammarians including prof. Vorontzova. Those who consider the perfect to be a part of the aspect system have expressed different opinions about the meaning of the Perfect forms.
The aspect expressed by the perfect forms has been defined as retrospective, resultative. The solution of the problem of the Perfect forms was found by the prominent Russian linguist. Smirnitsky whose contribution to the theory of the English verbs is great indeed. Prof. Smirn. paid attention to the peculiar structure of the Perfect Continuous forms in which the perfect form, which expresses priority, consists with the continuous form which denotes simultaneous actions. The gist of his reasoning was -that the perfect can not be either aspective or a temporal category because two expressions of one and the same category are impossible in one and the same form. So prof. Smirn. came to the conclusion that the opposition of perfect - non-perfect forms constitutes a special grammatical^^ category. He called this new category the_category of time correlation /the Sussian term категория временной относительности/ He published the results of his investigation in the journal “Foreign languages at school” in the article which he called “Перфект и категория временной соотнесённости”
Thus we see that the perfect forms by means of their opposition to the non-perfect forms build up their own category different both from the category of tense and the category of aspect. As we have already said prof. Smirn, called this category the category of time correlation. Later other terms for this category were suggested. Prof. Ilysh calls this category the category of correlation. In the book "A course in English Grammar" by Khaimovick and Rogovskaya this category is called the category of order or the category of time correlation. Some foreign linguists use the term “phase” e.g. Trager and Smith in the book "An outline of English Structure” Prof. Barchudarov in his book “Очерки по морфологии современного английского языка” also uses the term "phase". In the book "Theoretical English grammar” by Prof. Block this category is called the category of retrospective coordination