if 的英语意思
ifif1 /ɪf/ conjunction 
查看全部语言翻译1used when talking about something that might happen or be true, or might have happened用于谈论某事可能发生、可能是真的或可能已经发生的情况: 
We’ll stay at home if it rains.如果下雨，我们就待在家里。 If you need money, I can lend you some.如果你需要钱，我可以借给你一些。 If I didn’t apologize, I’d feel guilty.如果我不道歉，我会感到内疚。 If you had worked harder, you would have passed your exams.如果你当时更加努力，你本可以通过考试。 What would happen to your family if you were to die in an accident?如果你在一场事故中死去，你的家人会怎样？ If Dad were here, he would know what to do.如果爸爸在这里，他会知道该怎么做。 Taste the soup and add salt and pepper if necessary.尝一下汤，如有必要就加盐和胡椒。 I want to get back by five o’clock if possible.如果可能的话，我想在五点前回来。 I think I can fix it tomorrow. If not, you’ll have to wait till Friday.我想我明天能修好。如果不行，你就得等到周五了。 Is the book available, and if so, where?这本书有售吗？如果有的话，在哪里？ The missiles can be fired only if the operator types in a six-digit code.只有当操作员输入六位数密码时，导弹才能发射。 We’ll face that problem if and when it comes along (=if it happens or when it happens).那个问题如果出现，我们到时再面对（即如果发生或当发生时）。 If by any chance you can’t manage dinner tonight, perhaps we can at least have a drink together.如果你今晚碰巧无法来吃晚餐，也许我们至少可以一起喝一杯。2used to mention a fact, situation, or event that someone asks about, or is not certain about用于提及某人询问的或不确定的事实、情况或事件: He stopped to ask me if I was all right.他停下来问我是否一切都好。 I don’t know if what I am saying makes any sense.我不知道我说的话是否有道理。 I doubt if anyone will remember me.我怀疑是否会有人记得我。 I’m not sure if this is the right road or not.我不确定这是不是正确的路。3used to mention a type of event or situation when talking about what happens on occasions of that type用于谈论某类事件或情况时，说明该类情况下通常会发生什么: If I go to bed late, I feel dreadful in the morning.如果我睡得晚，早上就会感觉很糟糕。 Plastic will melt if it gets too hot.塑料如果太热就会融化。4used when saying what someone’s feelings are about a possible situation用于表达某人对某一可能情况的感受: You don’t seem to care if I’m tired.你好像不在乎我是否累了。 I’m sorry if I upset you.如果我让你心烦了，我很抱歉。 It would be nice if we could spend more time together.如果我们能多花些时间在一起就好了。5spoken口语 used when making a polite request用于礼貌地提出请求时: I wonder if you could help me.不知道您能否帮帮我。 I’d be grateful if you would send me further details.如果您能给我发送更多详情，我将不胜感激。 Would you mind if I open a window?您介意我开一下窗户吗？ If you would just wait for a moment, I’ll try to find your papers.如果您能稍等片刻，我来帮您找一下您的文件。6used when you are adding that something may be even more, less, better, worse etc than you have just said用于补充说某事实际上可能比刚才所说的更多、更少、更好或更差: Brian rarely, if ever, goes to bed before 3 am.布莱恩几乎从不在凌晨三点前上床睡觉，甚至可以说从来没有。 Their policies have changed little, if at all, since the last election.自上次选举以来，他们的政策几乎没有任何变化，甚至可以说毫无变化。 Her needs are just as important as yours, if not more so.她的需求和你的一样重要，甚至更为重要。 The snow was now two feet deep, making it difficult, if not impossible, to get the car out.雪已有两英尺深，要把车开出去很困难，甚至可以说不可能了。7even if used to emphasize that, although something may happen or may be true, it will not change a situation用于强调：尽管某事可能发生或可能为真，也不会改变当前的情况: I wouldn’t tell you even if I knew.即使我知道，我也不会告诉你。 Even if she survives, she’ll never fully recover.即使她活下来，也永远无法完全康复。8if anything used when adding a remark that changes what you have just said or makes it stronger用于补充一句话，以修正或加强刚才所说的内容: It’s warm enough here in London. A little too warm, if anything.伦敦这里已经够暖和了。说起来，甚至有点太热了。9spoken口语 used during a conversation when you are trying to make a suggestion, change the subject, or interrupt someone else在对话中，当你试图提出建议、转换话题或打断别人时使用: If I might just make a suggestion, I think that the matter could be easily settled with a little practical demonstration.如果我可以提个建议的话，我认为只需做一个简单的实际演示，这件事就可以轻松解决。 If I could just take one example to illustrate this.如果允许我举一个例子来说明这一点。10if I were you spoken口语 used when giving advice and telling someone what you think they should do用于提供建议、告诉某人你认为他们应该怎么做时: I wouldn’t worry about it if I were you.如果我是你，我不会为此担心的。11if only a)used to express a strong wish, especially when you know that what you want cannot happen用于表达强烈的愿望，尤其是当你知道所愿之事无法实现时: If only he had talked to her sooner!要是他早一点和她谈就好了！ If only I weren’t so tired!要是我没这么累就好了！ b)used to give a reason for something, although you think it is not a good one用于为某事给出理由，尽管你认为这个理由并不充分: Media studies is regarded as a more exciting subject, if only because it’s new.媒体研究被认为是一门更令人兴奋的学科，哪怕仅仅是因为它是新兴的。12used to say that, although something may be true, it is not important用于表示，虽然某事可能是真的，但它并不重要: If he has a fault at all, it is that he is too generous.如果说他有什么缺点的话，那就是他太慷慨了。 Her only problem, if you can call it a problem, is that she expects to be successful all the time.她唯一的问题——如果可以称之为问题的话——是她总是期望自己成功。13used when adding one criticism of a person or thing that you generally like用于对通常喜欢的人或事物附加一点批评时: The eldest son was highly intelligent, if somewhat lazy.长子非常聪明，只是有些懒。 Lunch was a grand if rather noisy affair.午餐是一场盛大的宴席，只是颇为嘈杂。 → as if at as2(9), → if ever there was one at ever(15), → what if ... ? at whatGRAMMAR语法Choosing the right tense选择正确的时态• You use if with the present tense, when talking about possible future events: · If I see him, I’ll tell him. ✗Don’t say: If I will see him, I’ll tell him.•谈论可能发生的未来事件时，if 与一般现在时连用：·If I see him, I'll tell him. ✗不要说：If I will see him, I'll tell him.• You use if with the past tense to talk about something that is unlikely or impossible: · If I won the lottery, I would leave my job. ✗Don’t say: If I would win the lottery ...•用 if 加过去式谈论不太可能或不可能的事：·If I won the lottery, I would leave my job. ✗不要说：If I would win the lottery…• In everyday spoken English, you say if I was: · If I was younger, I’d do it myself.•在日常口语英语中，说 if I was：·If I was younger, I'd do it myself.• In more formal English, you say if I were: · If I were in your position, I’d ask for help.•在较正式的英语中，说 if I were：·If I were in your position, I'd ask for help.• You use if with the past perfect to talk about something that did not happen: · If they had tried to stop the protest, there would have been a riot. ✗Don’t say: If they would have tried to stop the protest ...•用 if 加过去完成时谈论未曾发生的事：·If they had tried to stop the protest, there would have been a riot. ✗不要说：If they would have tried to stop the protest…• You also use if with the present perfect, when talking about whether something has happened or not: · If she hasn’t called by tomorrow, I’ll call her.Grammar guide ‒ VERBS•谈论某事是否发生时，也可用 if 加现在完成时：·If she hasn't called by tomorrow, I'll call her. 语法指南 ‒ 动词Comparison比较if• You say: · I’m not sure if I heard him correctly.· I don’t know if he is guilty.•可以这样说：·I'm not sure if I heard him correctly. ·I don't know if he is guilty.whether• You say: · I’m not sure whether I heard him correctly.· I don’t know whether he is guilty.•也可以这样说：·I'm not sure whether I heard him correctly. ·I don't know whether he is guilty.• You can use whether after a preposition: · We discussed the issue of whether to pay. ✗Don’t say: the issue of if to pay•介词后可以用 whether：·We discussed the issue of whether to pay. ✗不要说：the issue of if to pay• You can say whether to do something: · He doesn’t know whether to accept. ✗Don’t say: He doesn’t know if to accept.•可以说 whether to do something：·He doesn't know whether to accept. ✗不要说：He doesn't know if to accept.Grammar guide ‒ VERBSTHESAURUS同义词辨析if used when talking about the possibility that something might happen or be true用于谈论某事可能发生或可能为真的情况: · He faces a long prison sentence if the court finds him guilty.如果法庭判定他有罪，他将面临长期徒刑。· If scientists’ predictions are correct, average global temperatures could rise by 6 degrees.如果科学家的预测准确，全球平均气温可能会上升6度。unless if something does not happen, or if someone does not do something如果某事没有发生，或者某人没有做某事: · The star is difficult to see unless the sky is very clear.除非天空非常晴朗，否则这颗星很难看到。· Doctors said they could not treat the boy unless his parents gave their permission.医生说，除非男孩的父母同意，否则他们无法为他治疗。whether or not used when saying that it does not matter if something happens or not, or if something is true or not用于表示无论某事是否发生、或某事是否为真都没有关系: · Most people will get better on their own, whether or not they receive medical treatment.大多数人无论是否接受医疗，都会自行康复。· I’m still going, whether she likes it or not.不管她喜不喜欢，我都要去。otherwise used when saying that there will be a bad result if someone does not do something, or if something does not happen用于表示如果某人不做某事或某事不发生，将会有不良后果: · Drink plenty of water – otherwise you will become dehydrated.多喝水——否则你会脱水的。in case in order to deal with something that might happen为了应对可能发生的事情: · She did not think it would rain, but she took her umbrella just in case.她以为不会下雨，但还是带了伞以防万一。· It is best to keep a medical kit ready in case of emergency.最好随时备好急救包，以防紧急情况发生。as long as/provided that only if something else happens or is true只有在其他某事发生或为真的情况下才: · Visitors are welcome, as long as they bring their own tent.游客欢迎光临，只要自带帐篷即可。· Anyone can join the course, provided that there is space available.任何人都可以参加该课程，前提是有空位。· As long as you can find a computer, you can access an internet-based bank account wherever you are.只要能找到一台电脑，无论身在何处，你都可以访问网络银行账户。on condition that used when you agree to do something only if someone first agrees to do something else用于表示只有在对方先同意做某事的前提下，你才同意做某事: · He was offered the job on condition that he went on a month-long training course.他获得了这份工作，条件是必须参加为期一个月的培训课程。
查看全部语言翻译1used when talking about something that might happen or be true, or might have happened用于谈论某事可能发生、可能是真的或可能已经发生的情况: We’ll stay at home if it rains.如果下雨，我们就待在家里。 If you need money, I can lend you some.如果你需要钱，我可以借给你一些。 If I didn’t apologize, I’d feel guilty.如果我不道歉，我会感到内疚。 If you had worked harder, you would have passed your exams.如果你当时更加努力，你本可以通过考试。 What would happen to your family if you were to die in an accident?如果你在一场事故中死去，你的家人会怎样？ If Dad were here, he would know what to do.如果爸爸在这里，他会知道该怎么做。 Taste the soup and add salt and pepper if necessary.尝一下汤，如有必要就加盐和胡椒。 I want to get back by five o’clock if possible.如果可能的话，我想在五点前回来。 I think I can fix it tomorrow. If not, you’ll have to wait till Friday.我想我明天能修好。如果不行，你就得等到周五了。 Is the book available, and if so, where?这本书有售吗？如果有的话，在哪里？ The missiles can be fired only if the operator types in a six-digit code.只有当操作员输入六位数密码时，导弹才能发射。 We’ll face that problem if and when it comes along (=if it happens or when it happens).那个问题如果出现，我们到时再面对（即如果发生或当发生时）。 If by any chance you can’t manage dinner tonight, perhaps we can at least have a drink together.如果你今晚碰巧无法来吃晚餐，也许我们至少可以一起喝一杯。2used to mention a fact, situation, or event that someone asks about, or is not certain about用于提及某人询问的或不确定的事实、情况或事件: He stopped to ask me if I was all right.他停下来问我是否一切都好。 I don’t know if what I am saying makes any sense.我不知道我说的话是否有道理。 I doubt if anyone will remember me.我怀疑是否会有人记得我。 I’m not sure if this is the right road or not.我不确定这是不是正确的路。3used to mention a type of event or situation when talking about what happens on occasions of that type用于谈论某类事件或情况时，说明该类情况下通常会发生什么: If I go to bed late, I feel dreadful in the morning.如果我睡得晚，早上就会感觉很糟糕。 Plastic will melt if it gets too hot.塑料如果太热就会融化。4used when saying what someone’s feelings are about a possible situation用于表达某人对某一可能情况的感受: You don’t seem to care if I’m tired.你好像不在乎我是否累了。 I’m sorry if I upset you.如果我让你心烦了，我很抱歉。 It would be nice if we could spend more time together.如果我们能多花些时间在一起就好了。5spoken口语 used when making a polite request用于礼貌地提出请求时: I wonder if you could help me.不知道您能否帮帮我。 I’d be grateful if you would send me further details.如果您能给我发送更多详情，我将不胜感激。 Would you mind if I open a window?您介意我开一下窗户吗？ If you would just wait for a moment, I’ll try to find your papers.如果您能稍等片刻，我来帮您找一下您的文件。6used when you are adding that something may be even more, less, better, worse etc than you have just said用于补充说某事实际上可能比刚才所说的更多、更少、更好或更差: Brian rarely, if ever, goes to bed before 3 am.布莱恩几乎从不在凌晨三点前上床睡觉，甚至可以说从来没有。 Their policies have changed little, if at all, since the last election.自上次选举以来，他们的政策几乎没有任何变化，甚至可以说毫无变化。 Her needs are just as important as yours, if not more so.她的需求和你的一样重要，甚至更为重要。 The snow was now two feet deep, making it difficult, if not impossible, to get the car out.雪已有两英尺深，要把车开出去很困难，甚至可以说不可能了。7even if used to emphasize that, although something may happen or may be true, it will not change a situation用于强调：尽管某事可能发生或可能为真，也不会改变当前的情况: I wouldn’t tell you even if I knew.即使我知道，我也不会告诉你。 Even if she survives, she’ll never fully recover.即使她活下来，也永远无法完全康复。8if anything used when adding a remark that changes what you have just said or makes it stronger用于补充一句话，以修正或加强刚才所说的内容: It’s warm enough here in London. A little too warm, if anything.伦敦这里已经够暖和了。说起来，甚至有点太热了。9spoken口语 used during a conversation when you are trying to make a suggestion, change the subject, or interrupt someone else在对话中，当你试图提出建议、转换话题或打断别人时使用: If I might just make a suggestion, I think that the matter could be easily settled with a little practical demonstration.如果我可以提个建议的话，我认为只需做一个简单的实际演示，这件事就可以轻松解决。 If I could just take one example to illustrate this.如果允许我举一个例子来说明这一点。10if I were you spoken口语 used when giving advice and telling someone what you think they should do用于提供建议、告诉某人你认为他们应该怎么做时: I wouldn’t worry about it if I were you.如果我是你，我不会为此担心的。11if only a)used to express a strong wish, especially when you know that what you want cannot happen用于表达强烈的愿望，尤其是当你知道所愿之事无法实现时: If only he had talked to her sooner!要是他早一点和她谈就好了！ If only I weren’t so tired!要是我没这么累就好了！ b)used to give a reason for something, although you think it is not a good one用于为某事给出理由，尽管你认为这个理由并不充分: Media studies is regarded as a more exciting subject, if only because it’s new.媒体研究被认为是一门更令人兴奋的学科，哪怕仅仅是因为它是新兴的。12used to say that, although something may be true, it is not important用于表示，虽然某事可能是真的，但它并不重要: If he has a fault at all, it is that he is too generous.如果说他有什么缺点的话，那就是他太慷慨了。 Her only problem, if you can call it a problem, is that she expects to be successful all the time.她唯一的问题——如果可以称之为问题的话——是她总是期望自己成功。13used when adding one criticism of a person or thing that you generally like用于对通常喜欢的人或事物附加一点批评时: The eldest son was highly intelligent, if somewhat lazy.长子非常聪明，只是有些懒。 Lunch was a grand if rather noisy affair.午餐是一场盛大的宴席，只是颇为嘈杂。 → as if at as2(9), → if ever there was one at ever(15), → what if ... ? at whatGRAMMAR语法Choosing the right tense选择正确的时态• You use if with the present tense, when talking about possible future events: · If I see him, I’ll tell him. ✗Don’t say: If I will see him, I’ll tell him.•谈论可能发生的未来事件时，if 与一般现在时连用：·If I see him, I'll tell him. ✗不要说：If I will see him, I'll tell him.• You use if with the past tense to talk about something that is unlikely or impossible: · If I won the lottery, I would leave my job. ✗Don’t say: If I would win the lottery ...•用 if 加过去式谈论不太可能或不可能的事：·If I won the lottery, I would leave my job. ✗不要说：If I would win the lottery…• In everyday spoken English, you say if I was: · If I was younger, I’d do it myself.•在日常口语英语中，说 if I was：·If I was younger, I'd do it myself.• In more formal English, you say if I were: · If I were in your position, I’d ask for help.•在较正式的英语中，说 if I were：·If I were in your position, I'd ask for help.• You use if with the past perfect to talk about something that did not happen: · If they had tried to stop the protest, there would have been a riot. ✗Don’t say: If they would have tried to stop the protest ...•用 if 加过去完成时谈论未曾发生的事：·If they had tried to stop the protest, there would have been a riot. ✗不要说：If they would have tried to stop the protest…• You also use if with the present perfect, when talking about whether something has happened or not: · If she hasn’t called by tomorrow, I’ll call her.Grammar guide ‒ VERBS•谈论某事是否发生时，也可用 if 加现在完成时：·If she hasn't called by tomorrow, I'll call her. 语法指南 ‒ 动词Comparison比较if• You say: · I’m not sure if I heard him correctly.· I don’t know if he is guilty.•可以这样说：·I'm not sure if I heard him correctly. ·I don't know if he is guilty.whether• You say: · I’m not sure whether I heard him correctly.· I don’t know whether he is guilty.•也可以这样说：·I'm not sure whether I heard him correctly. ·I don't know whether he is guilty.• You can use whether after a preposition: · We discussed the issue of whether to pay. ✗Don’t say: the issue of if to pay•介词后可以用 whether：·We discussed the issue of whether to pay. ✗不要说：the issue of if to pay• You can say whether to do something: · He doesn’t know whether to accept. ✗Don’t say: He doesn’t know if to accept.•可以说 whether to do something：·He doesn't know whether to accept. ✗不要说：He doesn't know if to accept.Grammar guide ‒ VERBSTHESAURUS同义词辨析if used when talking about the possibility that something might happen or be true用于谈论某事可能发生或可能为真的情况: · He faces a long prison sentence if the court finds him guilty.如果法庭判定他有罪，他将面临长期徒刑。· If scientists’ predictions are correct, average global temperatures could rise by 6 degrees.如果科学家的预测准确，全球平均气温可能会上升6度。unless if something does not happen, or if someone does not do something如果某事没有发生，或者某人没有做某事: · The star is difficult to see unless the sky is very clear.除非天空非常晴朗，否则这颗星很难看到。· Doctors said they could not treat the boy unless his parents gave their permission.医生说，除非男孩的父母同意，否则他们无法为他治疗。whether or not used when saying that it does not matter if something happens or not, or if something is true or not用于表示无论某事是否发生、或某事是否为真都没有关系: · Most people will get better on their own, whether or not they receive medical treatment.大多数人无论是否接受医疗，都会自行康复。· I’m still going, whether she likes it or not.不管她喜不喜欢，我都要去。otherwise used when saying that there will be a bad result if someone does not do something, or if something does not happen用于表示如果某人不做某事或某事不发生，将会有不良后果: · Drink plenty of water – otherwise you will become dehydrated.多喝水——否则你会脱水的。in case in order to deal with something that might happen为了应对可能发生的事情: · She did not think it would rain, but she took her umbrella just in case.她以为不会下雨，但还是带了伞以防万一。· It is best to keep a medical kit ready in case of emergency.最好随时备好急救包，以防紧急情况发生。as long as/provided that only if something else happens or is true只有在其他某事发生或为真的情况下才: · Visitors are welcome, as long as they bring their own tent.游客欢迎光临，只要自带帐篷即可。· Anyone can join the course, provided that there is space available.任何人都可以参加该课程，前提是有空位。· As long as you can find a computer, you can access an internet-based bank account wherever you are.只要能找到一台电脑，无论身在何处，你都可以访问网络银行账户。on condition that used when you agree to do something only if someone first agrees to do something else用于表示只有在对方先同意做某事的前提下，你才同意做某事: · He was offered the job on condition that he went on a month-long training course.他获得了这份工作，条件是必须参加为期一个月的培训课程。ifif2 noun [countable] informal非正式 1ifs and buts British English, ifs, ands, or buts American English if you do not want any ifs and buts, you want someone to do something quickly without arguing如果你不想听任何"ifs and buts"，就是要某人不要争辩、立刻去做某事: No ifs and buts – just make sure the job is done by tomorrow!不要再说什么"如果"或"但是"——只管确保工作在明天之前完成！2and it’s a big if used to say that something is not likely to happen用于表示某事不太可能发生: The team will go racing next year if – and it’s a very big if – they can raise £6 million.这支车队明年将参加比赛——如果——而且这是个很大的"如果"——他们能筹集到600万英镑的话。3something that may or may not happen可能发生也可能不发生的事: There are too many ifs in this plan of yours.你这个计划里有太多"如果"了。
1ifs and buts British English, ifs, ands, or buts American English if you do not want any ifs and buts, you want someone to do something quickly without arguing如果你不想听任何"ifs and buts"，就是要某人不要争辩、立刻去做某事: No ifs and buts – just make sure the job is done by tomorrow!不要再说什么"如果"或"但是"——只管确保工作在明天之前完成！2and it’s a big if used to say that something is not likely to happen用于表示某事不太可能发生: The team will go racing next year if – and it’s a very big if – they can raise £6 million.这支车队明年将参加比赛——如果——而且这是个很大的"如果"——他们能筹集到600万英镑的话。3something that may or may not happen可能发生也可能不发生的事: There are too many ifs in this plan of yours.你这个计划里有太多"如果"了。