This study is about the principles for constructing polite speech. The core of it was published as Brown and Levinson (1978); here it is reissued with a new introduction which surveys the now considerable literature in linguistics, psychology and the social sciences that the original extended essay stimulated, and suggests new directions for research. We describe and account for some remarkable parallelisms in the linguistic construction of utterances with which people express themselves in different languges and cultures. A motive for these parallels is isolated - politeness, broadly defined to include both polite friendliness and polite formality - and a universal model is constructed outlining the abstract principles underlying polite usages. This is based on the detailed study of three unrelated languages and cultures: the Tamil of south India, the Tzeltal spoken by Mayan Indians in Chiapas, Mexico, and the English of the USA and England, supplemented by examples from other cultures. Of general interest is the point that underneath the apparent diversity of polite behaviour in different societies lie some general pan-human principles of social interaction, and the model of politeness provides a tool for analysing the quality of social relations in any society.