Register is a term used to indicate that different varieties of language will be used in different contexts - with context being understood to mean the situation, the purpose of the communication, the type of communication, the roles and relationships relationships between the participants in the communication, and various other factors. These factors may, for example, influence the choice of lexis used (eg technical or non-technical - elided or left out), the structures used (eg Sit down! or Would you like to take a seat?; We did a load of tests or A number of experiments were performed...), or the phonological features (eg in I'm going to talk about... , does the speaker say /gəʊwɪŋ tuː / or /gənə/ ?).
Halliday and Hasan (1976) divide these factors into field, mode and tenor of discourse:
Field of discourse : “the total event, in which the text is functioning, together with the purposive activity of the speaker or writer; it thus includes the subject-matter as one element in it” (1976 : 22).
Mode of discourse : “the function of the text in the event, including therefore both the channel taken by the language – spoken or written, extempore or prepared – and its genre, or rhetorical mode, as narrative, didactic, persuasive, phatic communion and so on” (1976: 22).
Tenor of discourse : "the type of role interaction, the set of relevant social relations, permanent and temporary, among the participants involved." (1976: 22).
Some examples :
- Field : A lecture on linguistics will use different language than a teacher might use in a beginners language course to describe grammar.
- Mode : A political speech, written to be spoken and presented to a large audience, and with a persuasive purpose will involve different language features to an anecdote recounted "on-the-spot" to an individual and intending to entertain.
- Tenor : The choice of a formal/informal, direct/indirect request exponent will be dependent on whether the participants are eg an adult speaking to a child or a shop assistant speaking to a customer. And even in these cases it will depend on status/affective involvement and frequency of contact.
Halliday, M., and Hasan, R. (1976) Cohesion in English, London : Longman