Prescriptivism and descriptivism
Throughout the ages, grammarians and linguists have been attempting to formulate the speakers’ grammar in a set of rules, though it is probably fair to say that they have not yet been able to do so completely for any language. This sense of grammar is known as descriptive grammar.
Unlike descriptive grammar, prescriptive grammar involves attempts to establish and maintain a standard of correctness in the language, to “prescribe” ( dictate ) and “proscribe” ( forbid ) certain ways of speaking.
Parole vs langue
Parole is a linguist term which describes part of native speakers’ implicit knowledge, which is innate, while langue is the actual use of language, what, may be quite incomplete and imperfect. These terms were conveyed by the Swiss linguist Ferdinand de Saussure.
RP
Received Pronunciation is a term which describes the British English accent, which is used by most announcers and newsreaders on serious national and international BBC broadcasting channels.
Phonology
When we talk about how phonemes function in language, and the relationship among the different phonemes – when, in other words, we study the abstract side of the sounds of the language – we are studying a related but different subject that we call phonology. A subdivision of phonology is phonetics, which is the study of the speech sounds of human language in general,