In linguistics, the "level" of formality of an utterance or text. In general, something like five levels will be identified (here from "highest" to "lowest"):
- Ceremonial language: ossified formulations, which may well use archaic grammatical and lexical forms, and which is used on specific occasions, often repeated by rote. "I, the undersigned, being of sound mind and body, do hereby call upon the person or persons duly appointed to secure the portal."
- Formal discourse: freely chosen language which complies fairly carefully to traditional grammatical standards or at least to the speaker's idea of them; lexical choices may tend towards the pedantic, learned, pompous or frilly. Most of this writeup, for example, or an academic lecture. "I would be most grateful if you could shut the door".
- 'Neutral', unmarked speech or writing; a somewhat chimerical concept. Normal speech is rarely perfectly grammatical; indeed, if transcribed it generally looks like gibberish. It relies heavily on intonation and extraverbal reference, and contains a high degree of redundant information. Neutral written language, if it existed, would avoid both colloquial forms (eg in English, contracted forms like I'd, should've1; in other European languages the use of familiar pronouns like tu, du, jij, vôce) as well as excessive floweriness; would probably not worry overmuch about compliance with the niceties of prescriptive grammar (such as split infinitives or the less/fewer distinction in English), whilst complying with the underlying syntactical structures of the language. "Please shut the door".
- Colloquial speech or writing: discourse where specific grammatical, lexical and pragmatic forms are used to indicate that the situation is informal, but where the vast majority of the semantic content is explicitly included. Lexical items which would be shunned in higher registers for one reason or another may well be included. The underlying syntactic structures still apply, but spoken forms will generally be extremely fragmentary. "Can you shut the door, mate?"
- Familiar speech (rarely written). Speech where the level of intimacy between the participants is (or is assumed to be by the git who is effing and blinding at you) such that a high proportion of the semantic content can be omitted or referred to only implicitly or elliptically. "Born in a fucking barn, were we?"
There are clearly a number of sociolinguistic factors which determine how any given utterance may be intended or received; it is of course more of a continuum than a set of discrete levels.
Register errors - using "inappropriate" levels of language, producing an utterance which is likely to be taken as either pompous, rude, or just plain weird - are an issue in various linguistic fields; they are a common problem for language learners. An anglophone learner of Italian may find the uninflected "cui" construction (for "which") easier to use than the alternative gender-inflected "il quale/la quale/i quali/le quali" form, but the former is in fact rather high-flown for normal speech; conversely, Italians learning English are likely to overuse Latin-root cognates of their familiar Italian verbs rather than the Germanic-rooted prepositional and phrasal verbs which sound "simpler" to English speaker's ears ("establish" or "construct" rather than "set up", for example).
1. These contracted forms in written English represent elision and articulation which occurs in all but the most formal registers of speech, but they are generally considered to be markers of a fairly colloquial register if they are used in writing, particularly outside direct speech. By contrast many similar phenomena in other spoken European languages are formalised into the writing system and used for all registers (e.g. Italian della = di + la, German zum = zu + dem, Portuguese á = a + a ) or a wider range (e.g. Dutch m'n, z'n for unstressed mijn, zijn).