if

英 [ɪf]

美 [ɪf]

conj.  如果; 假若; 倘若; 当; 无论何时; 每次; 与will或would连用，表示客气地请求
n.  不确定的情况

中考高考CET4考研计算机

Oxford 3000 / Collins.5 / BNC.40 / COCA.40

习惯用语

conj.

if and when
• （谈及可能发生或不发生的事时说）
  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.
  倘若我们再次见面，我希望他还记得我为他做的事。
if anything
• （表达看法，或用在否定句之后表示反面意见才对）
  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.
  依我看，如果一定要说他像谁的话，他比较像他的父亲。
• She's not thin─if anything she's on the plump side.
  她并不瘦——其实她还有点胖呢。
if I were you
• （提出劝告时说）
  used to give sb advice
• If I were you I'd start looking for another job.
  我要是你，就会去另找工作了。
if not
• （用在if引导的句子之后）不然，要不
  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.
  你去我就去。不然的话，我宁愿待在家里。
• （用于yes / no疑问句之后，表示如果答案是no，将会或应该发生什么）
  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.
  你准备好了吗？否则我就自己去了。
• Do you want that cake? If not, I'll have it.
  你要那块蛋糕吗？不然我就要了。
• （表示可能更大或更重要等）
  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.
  建设要耗费数千英镑，甚至可能是数百万英镑。
if only
• 但愿
  used to say that you wish sth was true or that sth had happened
• If only I were rich.
  但愿我很富有。
• If only I knew her name.
  我要是知道她的名字就好了。
• If only he'd remembered to send that letter.
  要是他没忘记发那封信就好了。
• If only I had gone by taxi.
  我要是乘出租车去就好了。
it's not as if
• （表示所发生的事情令人惊讶）
  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.
  我很惊讶他们居然请我参加他们的婚礼——我跟他们似乎并不熟。
only if
• 只有
  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.
  学生只有得到老师的许可才能离开教室。
• Only if the red light comes on is there any danger to employees.
  只有红灯闪亮时才有危及职工的险情。

牛津词典

conj.

• 如果；假若；倘若
  used to say that one thing can, will or might happen or be true, depending on another thing happening or being true
  1. If you see him, give him this note.
     你要是见到他，就把这个便条给他。
  2. I'll only stay if you offer me more money.
     你给我更多的钱我才会留下。
  3. If necessary I can come at once.
     如果有必要，我可以马上来。
  4. You can stay for the weekend if you like.
     你如果愿意就留在这里过周末吧。
  5. If anyone calls, tell them I'm not at home.
     要是有人打电话来，就说我不在家。
  6. If he improved his IT skills, he'd (= he would) easily get a job.
     他如果提高了自己的信息技术技能，就会容易找到工作。
  7. You would know what was going on if you'd (= you had) listened.
     你若是注意听了，就会知道发生什么事了。
  8. They would have been here by now if they'd caught the early train.
     假若他们赶上了早班火车，现在就该到这里了。
  9. If I was in charge, I'd do things differently.
     假若由我负责，我不会这样办事的。
  10. If I were in charge…
      假若由我负责…
  11. Even if (= although) you did see someone, you can't be sure it was him.
      即使你确实看见有个人，也不能保证那就是他。
• 当；无论何时；每次
  when; whenever; every time
  1. If metal gets hot it expands.
     金属受热就膨胀。
  2. She glares at me if I go near her desk.
     我一走近她的办公桌，她就对我瞪眼。
• （与will或would连用，表示客气地请求）
  used with will or would to ask sb politely to do sth
  1. If you will sit down for a few moments, I'll tell the manager you're here.
     请稍坐，我这就告诉经理说您来了。
  2. If you would care to leave your name, we'll contact you as soon as possible.
     麻烦您留下姓名，我们会尽快与您联系的。
• （用于ask、know、find out、wonder等之后，引出两个或以上的可能性之一）是否
  used after ask , know , find out , wonder , etc. to introduce one of two or more possibilities
  1. Do you know if he's married?
     你知道他结婚了吗？
  2. I wonder if I should wear a coat or not.
     我不知道该不该穿外套。
  3. He couldn't tell if she was laughing or crying.
     他弄不清楚她是在笑还是在哭。
  4. Listen to the tune and see if you can remember the words.
     听听曲调，看你能否记起歌词。
• （用于表示情感的动词或形容词之后）
  used after verbs or adjectives expressing feelings
  1. I am sorry if I disturbed you.
     很抱歉，打搅您了。
  2. I'd be grateful if you would keep it a secret.
     你如果能对此保密，我将不胜感激。
  3. Do you mind if I turn the TV off?
     我关上电视可以吗？
• （承认某事可能，但不很重要）即使，虽然
  used to admit that sth is possible, but to say that it is not very important
  1. If she has any weakness, it is her Italian.
     如果要说她有什么缺点，那就是她的意大利语不大行。
  2. So what if he was late. Who cares?
     他就是迟到了又怎么样。谁在乎？
• （置于形容词之前，引出对比）虽然，尽管
  used before an adjective to introduce a contrast
  1. He's a good driver, if a little over-confident.
     他是个好司机，虽然有点过于自信。
  2. We'll only do it once─ if at all .
     我们就是干也只会干一次。
• （请对方听自己的意见）
  used to ask sb to listen to your opinion
  1. If you ask me, she's too scared to do it.
     依我看，她被吓得不敢做了。
  2. If you think about it, those children must be at school by now.
     想想吧，那些孩子现在一定在学校了。
  3. If you remember, Mary was always fond of animals.
     记得吧，玛丽总是喜欢动物。
• （置于could、may或might之前，以提出建议或客气地打断别人的话）
  used before could , may or might to suggest sth or to interrupt sb politely
  1. If I may make a suggestion, perhaps we could begin a little earlier next week.
     我来提个建议吧，或许我们下个星期可以早一点开始。

noun

• 不确定的情况
  a situation that is not certain
  1. If he wins─and it's a big if ─he'll be the first Englishman to win for fifty years.
     假设他赢了——不过这还是个很大的疑问——他将成为五十年以来第一个获胜的英格兰人。
  2. There are still a lot of ifs and buts before everything's settled.
     在一切得以解决之前还有很多不定因素。

柯林斯词典

Often pronounced /'ɪf/ at the beginning of the sentence. 在句首常重读。


• CONJ-SUBORD (表示条件或假设)假如，如果，要是
  You useifin conditional sentences to introduce the circumstances in which an event or situation might happen, might be happening, or might have happened.
  1. She gets very upset if I exclude her from anything...
     要是有什么事情我不让她参加,她会非常难过。
  2. You'll feel a lot better about yourself if you work on solutions to your upsetting situations...
     如果你设法找到解决自己麻烦的办法,你自我感觉会好得多。
  3. You can go if you want...
     你要是想走就可以走。
  4. If you would like to send a donation to Cobuild, please enclose a cheque with your coupon...
     如果你想为Cobuild语料库捐款,请随订货单附上支票。
  5. If you went into town, you'd notice all the pubs have loud jukeboxes...
     如果你进了城,你会注意到所有的酒吧都有音量很大的自动点唱机。
  6. What I did was right and if I had done anything less it would have been wrong...
     我做的一切都是正确的,如果我少做了一点点,就会出错。
  7. Fry remaining peppers, adding a little more dressing if necessary...
     用油炸一下剩下的辣椒,如果需要再加点调味汁。
  8. Do you have a knack for coming up with ideas? If so, we would love to hear from you.
     你有什么能想出好点子的诀窍吗？如果有,我们很愿意收到你的来信。
• CONJ-SUBORD (用于间接疑问句)是否
  You useifin indirect questions where the answer is either 'yes' or 'no'.
  1. He asked if I had left with you, and I said no...
     他问我是否和你一块儿离开的,我说不是。
  2. I wonder if I might have a word with Mr Abbot?
     请问我能否和阿博特先生说几句话？
• CONJ-SUBORD (表示与句子主要部分的陈述稍有不同)即便，纵然，虽然
  You useifto suggest that something might be slightly different from what you are stating in the main part of the sentence, for example that there might be slightly more or less of a particular quality.
  1. Sometimes, that standard is quite difficult, if not impossible, to achieve...
     有时即便有可能达到那个标准，那也是非常困难。
  2. I'm working on my fitness and I will be ready in a couple of weeks, if not sooner...
     我正在调养身体,最多两三周以后就可以了。
  3. Many, if not most, scientific papers are presented orally at scientific meetings...
     许多科学论文,即便不是大多数,都是以口头形式在科学会议上发表的。
  4. What one quality, if any, do you like the most about your partner?...
     你最喜欢你伴侣的哪一点,假如有的话？
  5. Meat was available once a week if at all.
     就算有肉，也是每周才吃一次。
• CONJ-SUBORD 如果…可以的话(通常与can，could, may 或 might 连用,在谈话中礼貌地提出自己的观点、转换话题或打断对方)
  You useif, usually with 'can', 'could', 'may', or 'might', at a point in a conversation when you are politely trying to make a point, change the subject, or interrupt another speaker.
  1. If I could just make another small point about the weightlifters in the Olympics...
     请允许我就有关奥运会举重运动员的问题再补充一点。
  2. So, if we may return strictly to athletics again for a few minutes...
     因此,如果我们可以再花几分钟重新回到田径运动话题上来的话……
  3. But if I can interrupt, Joe, I don't think anybody here is personally blaming the Germans...
     但是请允许我打断一下，乔,我认为在场的任何人都没有谴责德国人的意思。
  4. Well, it's the old argument Max, which is a bit ridiculous if you don't mind me saying so...
     哦,马克斯，又是那个很老套且有点儿荒谬的争论,如果你不介意我这么说的话。
  5. Well if you want my opinion, unless you do it soon you're gonna lose the opportunity and you'll be really sorry.
     如果你想听我的意见,你应该尽快做那事,否则你会失去机会,并且会非常遗憾。
• CONJ-SUBORD (用于句首，表示礼貌地请求某人做某事)
  You useifat or near the beginning of a clause when politely asking someone to do something.
  1. I wonder if you'd be kind enough to give us some information, please?
     请问您能不能给我们提供一些信息？
  2. If you will just sign here, we will arrange for your bank to deduct your payments automatically.
     麻烦您在这里签一下字,我们将联系您的银行自动扣除您的付款。
• CONJ-SUBORD (用于引导从句中较次要的事实)即便
  You useifto introduce a subordinate clause in which you admit a fact which you regard as less important than the statement in the main clause.
  1. If there was any disappointment it was probably temporary...
     即便有点儿失望,也肯定是暂时的。
  2. Even if I'm overstating the case for nutrition, at least it will result in the woman being in charge of her own symptoms...
     即便我夸大了营养的重要性,但至少它会让这个女人知道关注自己的症状。
  3. So what if sometimes they stayed rather late, it doesn't mean anything.
     因此，即便有时他们熬夜到很晚,那也说明不了什么。
• PHR-CONJ-SUBORD 要是不;即使不
  You useif notin front of a word or phrase to indicate that your statement does not apply to that word or phrase, but to something closely related to it that you also mention.
  1. A number of recent advances hold out if not the hope of a cure, then at least the possibility of some drug which could stop the spread of the virus...
     近来的一些进展即使不能提供治愈的希望,也至少有望研制出来某种药物来阻止病毒的传播。
  2. She understood his meaning, if not his words, and took his advice.
     她即便没听懂他的话,也明白了他的意思,并且接受了他的建议。
• PHR-CONJ-SUBORD (用于过去时,加强语气)如果真的…
  You useif everwith past tenses when you are introducing a description of a person or thing, to emphasize how appropriate it is.
  1. I became a distraught, worried mother, a useless role if ever there was one...
     我变成了一个忧心如焚的母亲,一个全无用处的角色。
  2. If ever there was the right person in the right job it was she...
     要是真的有才尽其用的人,那就是她。
  3. If ever a man needed your love, I need it.
     如果说真有一个男人需要你的爱,那就是我。
• PHR-CONJ-SUBORD (与过去时连用，引出一个相对合理的理由)即使仅仅为了(或因为)…
  You useif onlywith past tenses to introduce what you think is a fairly good reason for doing something, although you realize it may not be a very good one.
  1. She writes me often, if only to scold me because I haven't written to her...
     她常来信,即使仅仅为了责怪我还没回信给她。
  2. A one-to-one meeting with the US President was necessary, if only for a deeper exchange of views.
     与美国总统一对一的会谈是必要的,即便仅仅是为了双方观点更深入的交流。
• PHR-CONJ-SUBORD 要是…多好
  You useif onlyto express a wish or desire, especially one that cannot be fulfilled.
  1. If only you had told me that some time ago...
     要是你早些时候告诉我该多好啊！
  2. If only it were that simple!...
     要是那么简单就好了！
  3. 'Hey, listen to me, all that 1980 nonsense is over.' — 'If only, Timothy, if only.'
     “嗨,听我说,所有那些 1980 年的无聊之事都结束了。”——“要是这样就好了,蒂莫西,要是这样就好了。”
• PHR-CONJ-SUBORD (表示判断)好像,仿佛,似乎
  You useas ifwhen you are making a judgment about something that you see or notice. Your belief or impression might be correct, or it might be wrong.
  1. The whole room looks as if it has been lovingly put together over the years...
     整个房间看起来好像是经过了多年的精心布置。
  2. His heart was pounding, as if he were frightened.
     他的心怦怦跳,似乎被吓坏了。
• PHR-CONJ-SUBORD (表示类比)好像，仿佛，似乎
  You useas ifto describe something or someone by comparing them with another thing or person.
  1. He points two fingers at his head, as if he were holding a gun...
     他把两根手指指向他的头,仿佛他正举着一支枪。
  2. The two cousins looked as if they'd been carved from blocks of ice.
     两个堂姊妹看起来像由冰块雕刻而成。
• PHR-CONJ-SUBORD (强调某物不是真的)好像…一样,仿佛,似乎
  You useas ifto emphasize that something is not true.
  1. My husband, for some unknown reason, suggested that I loved my birds more than him: as if I would...
     我丈夫,莫名其妙地,暗示我爱鸟甚于爱他：仿佛我真如此似的。
  2. Getting my work done! My God! As if it mattered.
     把我的工作做完！老天！好像它真的很重要似的。
• PHRASE 要说真有什么的话;甚至正相反
  You use 'if anything' to introduce something which strengthens or changes the meaning of the statement you have just made, but only in a small or unimportant way.
  1. Living together didn't harm our friendship. If anything it strengthened it...
     在一起住并没有损害我们的友谊。要说真有什么的话,它反而巩固了我们的友谊。
  2. Asthma drugs are not addictive and you don't need to keep increasing the dose. If anything, the reverse is true.
     哮喘药物不会造成药物依赖,你不用持续增大剂量。甚至正相反,减小剂量才对。
• PHRASE 显然不是
  You use 'It's not as if' to introduce a statement which, if it were true, might explain something puzzling, although in fact it is not true.
  1. I am surprised by the fuss she's making. It's not as if my personality has changed.
     她的大惊小怪令我很吃惊。显然不是我的个性改变了。
• PHRASE (用于给人建议)如果我是你的话
  You say 'if I were you' to someone when you are giving them advice.
  1. If I were you, Mrs Gretchen, I just wouldn't worry about it...
     要是我是你,格蕾琴夫人,我一点都不会担心。
  2. What I'd do if I were you is be nice to him...
     如果我是你,我要做的就是对他好。
  3. I should lie down for a bit, if I were you.
     如果我是你,我就会躺一会儿。

双语例句

• Fry remaining peppers, adding a little more dressing if necessary
  用油炸一下剩下的辣椒，如果需要再加点调味汁。
• I'm working on my fitness and I will be ready in a couple of weeks, if not sooner
  我正在调养身体，最多两三周以后就可以了。
• Sometimes, that standard is quite difficult, if not impossible, to achieve
  有时即便有可能达到那个标准，那也是非常困难。
• What I did was right and if I had done anything less it would have been wrong
  我做的一切都是正确的，如果我少做了一点点，就会出错。
• I wonder if you'd be kind enough to give us some information, please?
  请问您能不能给我们提供一些信息？
• She gets very upset if I exclude her from anything
  要是有什么事情我不让她参加，她会非常难过。
• If I were you, Mrs Gretchen, I just wouldn't worry about it
  要是我是你，格蕾琴夫人，我一点都不会担心。
• I became a distraught, worried mother, a useless role if ever there was one
  我变成了一个忧心如焚的母亲，一个全无用处的角色。
• Well if you want my opinion, unless you do it soon you're gonna lose the opportunity and you'll be really sorry.
  如果你想听我的意见，你应该尽快做那事，否则你会失去机会，并且会非常遗憾。
• If I could just make another small point about the weightlifters in the Olympics
  请允许我就有关奥运会举重运动员的问题再补充一点。