Intonation refers to patterns of pitch that carry meaningful information. There are four main types: fall, rise, fall-rise, and rise-fall. Intonation serves attitudinal, accentual, grammatical, and discourse functions to express feelings, stress words, and help listeners understand grammar, syntax, and new versus given information. Received Pronunciation (RP) was historically used by the British aristocracy but has changed over time with the emergence of new accents like Cockney, working class, and Estuary English, described in 1984 as originating near the Thames. RP has undergone several phonological changes in its pronunciation of consonants and diphthongs.