A sentence that overrode all of its reader's primings … would not correspond to anything recognizable as an instance of language in use".
Each instance of language as text is an instantiation of the semiotic system, as expressed by individuals through the linguistic choices they make while interacting with other social human beings (Halliday 2004).
Although the notion of system of a particular language itself cannot ever be considered to be fully decontextualized, since it has been shaped by the culture of the language users, it involves a higher degree of decontextualization than a particular instance of language.
Fitzgerald found several nearly unique instances of language usage — a preference for pompous vocabulary such as "dubiety," "redoubt," and other ponderous phrasings.
To the learner of English, often brought up on a diet of grammar rules and comfortably defined meanings, such instances of language use, while commonplace, often seem to defy analysis.
But since traditional metaphysics and epistemology are prime instances of language gone on conceptually confused holiday, definitions of art share in the conceptual confusions of traditional philosophy (Tilghman).
If this was not the case, then (considering spoken language) one would expect to find actual instances of language use which exhibit grammatical properties but not phonological ones.
There is often a conflict for the analyst when trying to determine what the speaker has done with language and how the model used by the analyst can fit the instances of language being analysed.
Rather it is likely that the functional role of instances of language, gesture, and inscription shift fluidly for these learners as they move between individual reflection, self-explanation, attending to their interlocutor, and working to construct inferences in their dyad.
The notion of potentials is fundamental in systemic theorising, because it allows the linguistic model to apply not just to previously encountered linguistic utterances, but also to additionally try to explain how speakers produce and interpret novel instances of language.
Therefore, it is more contextualized than the overall system, which must cover all potential instances of language use, but less contextualized than a text, which is intimately tied to the particular setting in which it was created.
