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English definition of “by”


preposition (NOT LATER THAN)    /baɪ/
A2 not later than; at or before: She had promised to be back by five o'clock. The application must be in by the 31st to be accepted. By the time I got to the station the train had already gone.Before, after and alreadyAfter and behind Grammar:Before, by, till, untilIf you have to do something before a certain point in time, then when that point arrives, the action must already be completed:See moreGrammar:ByBy is a preposition or an adverb.See moreGrammar:By and timeWe use by meaning ‘not later than’ to refer to arrangements and deadlines:See moreGrammar:By and the passiveWhen we use the passive voice, we can use a phrase with by to say who did the action:See moreGrammar:By meaning ‘how to do something’We use by + -ing form to describe how to do something:See moreGrammar:By + myself etc.When we say by + myself, yourself, himself, herself, itself, oneself, ourselves, yourselves, themselves, it means ‘alone’. We sometimes use all for emphasis:See moreGrammar:By and placeWe use by to mean ‘beside’ or ‘at the side of’:See moreGrammar:By and measurements and amountsWe use by to talk about measurements, and increases and decreases in amounts:See moreGrammar:By meaning ‘during’We sometimes use by + day and by + night to mean ‘during the day or the night’:See moreGrammar:By meaning ‘written’ or ‘composed’We use by when we talk about the writers of books, songs, poems, symphonies, etc.:See moreGrammar:By: typical errorsSee more
(Definition of by preposition (NOT LATER THAN) from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
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