if

conjunction, noun conjunction 1 used to say that one thing can, will or might happen or be true, depending on another thing happening or being true: If you see him, give him this note. * I'll only stay if you offer me more money. * If necessary I can come at once. * You can stay for the weekend if you like. * If anyone calls, tell them I'm not at home. * If he improved his IT skills, he'd (= he would) easily get a job. * You would know what was going on if you'd (= you had) listened. * They would have been here by now if they'd caught the early train. * If I was in charge, I'd do things differently. * (rather formal) If I were in charge... * Even if (= although) you did see someone, you can't be sure it was him. 2 when; whenever; every time: If metal gets hot it expands. * She glares at me if I go near her desk. 3 (formal) used with will or would to ask sb politely to do sth: If you will sit down for a few moments, I'll tell the manager you're here. * If you would care to leave your name, we'll contact you as soon as possible. 4 used after ask, know, find out, wonder, etc. to introduce one of two or more possibilities SYNWHETHER: Do you know if he's married? * I wonder if I should wear a coat or not. * He couldn't tell if she was laughing or crying. * Listen to the tune and see if you can remember the words. 5 used after verbs or adjectives expressing feelings: I am sorry if I disturbed you. * I'd be grateful if you would keep it a secret. * Do you mind if I turn the TV off? 6 used to admit that sth is possible, but to say that it is not very important: If she has any weakness, it is her Italian. * So what if he was late. Who cares? 7 used before an adjective to introduce a contrast: He's a good driver, if a little over-confident. * We'll only do it once-if at all. 8 used to ask sb to listen to your opinion: If you ask me, she's too scared to do it. * If you think about it, those children must be at school by now. * If you remember, Mary was always fond of animals. 9 used before could, may or might to suggest sth or to interrupt sb politely: If I may make a suggestion, perhaps we could begin a little earlier next week. IDIOMS if and when used to say sth about an event that may or may not happen: If and when we ever meet again I hope he remembers what I did for him. if anything used to express an opinion about sth, or after a negative statement to suggest that the opposite is true: I'd say he was more like his father, if anything. * She's not thin-if anything she's on the plump side. if I were you used to give sb advice: If I were you I'd start looking for another job. if not 1 used to introduce a different suggestion, after a sentence with if: I'll go if you're going. If not (= if you are not) I'd rather stay at home. 2 used after a yes/no question to say what will or should happen if the answer is 'no': Are you ready? If not, I'm going without you. * Do you want that cake? If not, I'll have it. 3 used to suggest that sth may be even larger, more important, etc. than was first stated: They cost thousands if not millions of pounds to build. if only used to say that you wish sth was true or that sth had happened: If only I were rich. * If only I knew her name. * If only he'd remembered to send that letter. * If only I had gone by taxi. it's not as if (spoken) used to say that sth that is happening is surprising: I'm surprised they've invited me to their wedding-it's not as if I know them well. only if (rather formal) used to state the only situation in which sth can happen: Only if a teacher has given permission is a student allowed to leave the room. * Only if the red light comes on is there any danger to employees. noun (informal) a situation that is not certain: If he wins-and it's a big if-he'll be the first Englishman to win for fifty years. * There are still a lot of ifs and buts before everything's settled. ______________________________ GRAMMARPOINT if / whether Both if and whether are used in reporting questions which expect 'yes' or 'no' as the answer: She asked if /whether I wanted a drink., although whether sounds more natural with particular verbs such as discuss, consider and decide. When a choice is offered between alternatives if or whether can be used: He didn't know if /whether we should write or phone. In this last type of sentence, whether is usually considered more formal and more suitable for written English. ______________________________