Every intelligible sentence exchanged by talkers, for example, presupposes a practical mastery of the grammar, the syntax, and the morphology of the language in use. The talkers do not make use of all the possible linguistic rules for every sentence, but every intelligible utterance entails, none the less, a prodigious and complex set of rules. This set of rules becomes effectively present in its absence, in its evanescent instantiation in every sentence spoken.
“Language is what language does” (Social Theory and Modern Sociology), or “language is practical consciousness” (Karl Marx). Language is practical, as it facilitates social intercourse, which reproduces it as a social product. A living language is never private property, and it can never be withheld from the other talkers, who regularly appropriate it.
The regular use of language by every communicative person renders the linguistic structure not only present but also evanescent, as every intelligible expression momentarily reproduces and potentially modulates the structure. As an intelligible expression unfolds in empirical time-space, the linguistic structure is reproduced in virtual time-space.
A good illustration of the practical, pliable, and evanescent aspects of the linguistic structure is the phenomenon of the ordinary conversation, which never entails strict rules. Within the flow of conversation, some half-sentences, subjectless remarks, verbless expressions, and prepositional phrases can become crucial moments of communication.
The actual intelligibility of grammatically vague or mangled expressions disrupts the linguistic structure and “corrupts” or modifies its rules. Yet it is precisely the practical mastery of the rules of a particular language, as is usually the case with native speakers, which enables conversationalists every now and then to suspend some of the rules without thereby turning their talk into a babel of voices. The competent suspension of rules is an instance of the presence-in-absence of structure.
Today, most non-aboriginal languages have grammatical rules and standard lexical items in writing, but the practical reality of a living language enables some widely-used slang and colloquial expressions to be accepted eventually into formal speech and writing. Furthermore, every standard lexical item can acquire novel connotations or even additional definitions through frequent application outside the usual contexts.
In the same process, formal expressions can fall into such disuse that they eventually disappear even from specialized texts. This is a continuous process of the appearance, disappearance, and modification of the verbal expressions and their connotations, and thus the linguistic structure is never, at any moment, simply itself.
The actual intelligibility of vague or inexact expressions, especially during conversation, depends on a mastery not only of linguistic rules, but more so, of corporal and contextual rules and resources. A mastery of these rules and resources entails a “ramified control of the body and a developed knowledge of how to ‘go on’ in the plurality of contexts of social life” (Constitution of Society).