Что такое стилистика в английском языке?

Stylistics can be defined as a branch of modern linguistics devoted to the detailed analysis of literary style, or of the linguistic choices made by speakers and writers in non-literary contexts. (Chris Baldick Oxford Concise Dictionary of Literary Terms, 1996)
According to I.R. Galperin, stylistics is a branch of general linguistics, which deals with the investigation of two independent tasks:
Stylistics studies the special media of language which are called stylistic devices and expressive means.
Stylistics studies the types of texts which are distinguished by the pragmatic aspect of the communication and are called functional styles of language.
Expressive means of a language are those phonetic, morphological, word-building, lexical, phraseological and syntactical forms which exist in language-as-a-system for the purpose of logical and/or emotional intensification of the utterance. (Galperin, 27). These intensifying forms have special functions in making the utterances emphatic.
According to I.V. Arnold, "stylistics is a branch of linguistics, which studies the principles and results of the choice and usage of lexical, grammatical, phonetic and other language means with the aim of transmitting of ideas and emotions in different communication settings." ("Стилистикой называется отрасль лингвистики, исследующая принципы и эффект выбора и использования лексических, грамматических, фонетических и вообще языковых средств для передачи мысли и эмоции в разных условиях общения. " (cтр. 7))
почитай еще Гальперина
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1)есть разные стили написания письма (варианты написания) -это зависит от того кому ты пишешь и о чем пишешь
2)разные стили сочинений и т. п.