Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English


English definition of “if”


conjunction (WHETHER)    /ɪf/
B1 used to introduce a clause , often in indirect speech , that shows two or more possibilities : Mrs Kramer called half an hour ago to ask if her cake was ready . I don't care if he likes it or not - I'm coming! I was wondering if you'd like to come to the cinema with me this evening ? → Compare whetherConnecting words which express a condition whetherGrammar:IfIf is a conjunction.Grammar:Whether not ifWe use whether and not if after prepositions:Grammar:I doubt if, I don’t know whetherWe use if or whether to introduce clauses after verbs of doubting:Grammar:If, whether: typical errors[talking about a trip to Australia for a year]Grammar:If or when?We use if to introduce a possible or unreal situation or condition. We use when to refer to the time of a future situation or condition that we are certain of:Grammar:If: conditionsWe often use if to introduce possible or impossible situations or conditions and their results. The situations or conditions can be real, imagined or uncertain:Grammar:If possible, if necessaryWe can sometimes leave words out after if to form fixed expressions:Grammar:If so, if notWe use so or not after if when it is obvious what we are referring to:Grammar:Even ifWe can use even if to mean if when talking about surprising or extreme situations:Grammar:If: reporting questionsWe use if to introduce reported yes-no questions and questions with or.Grammar:If and politenessIn speaking, we often use if to introduce a polite request. If is usually followed by modal verbs will, would, can or could when it is used to be polite:Grammar:If or whether?Grammar:If and whether: indirect questionsWe can use if or whether to report indirect yes-no questions and questions with or. If is more common than whether:Grammar:When or if?We use when to refer to a future situation or condition that we are certain of, whereas we use if to introduce a possible or unreal situation.
(Definition of if conjunction (WHETHER) from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
Focus on the pronunciation of if

Definitions of “if” in other dictionaries

Word of the Day


to pour liquid slowly over something, especially in a thin line or in small drops

Word of the Day


Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More