詞語：if
if是什麼意思
簡明英漢詞典
if
[if]
conj.
(表條件)如果, (表假設)要是, 是否, 即使
n.
條件, 設想
基本詞義
IF
=Information Collector 信息收集器
美國傳統詞典[雙解]
if
if
AHD:[1f]
D.J.[if]
K.K.[!f]
conj.（連接詞）
(1)In the event that:
如果，倘若：在…的情況下：
If I were to go, I would be late.
倘若我去，就要遲到
(2)Granting that:
假設，如果：
If that is true, what should we do?
假設那是真的我們該怎麼辦呢?
(3)On the condition that:
如果，只要：在某種條件下：
She will play the piano only if she is paid.
只有付給她報酬，她才願意演奏鋼琴
(4)Although possibly; even though:
雖然；即使：
It is a handsome if useless trinket.
雖然無用卻很漂亮的小飾物
(5)Whether:
是否：
Ask if he plans to come to the meeting.
問問他是否要來參加會議
(6)Used to introduce an exclamatory clause, indicating a wish:
但願，要是…該多好啊：用來引出一個表達願望的感歎句，表達一個願望：
If they had only come earlier!
如果他們早來一步該多好啊!
n.（名詞）
A possibility, condition, or stipulation:
條件：可能性、條件或設想：
There will be no ifs, ands, or buts in this matter.
這件事不允許有假設、拖延或反對
語源
(1)Middle English
中古英語
(2)from Old English gif * see i-
源自 古英語 gif *參見 i-
用法
(1)In informal writing both if and whether are standard in their use to introduce a clause indicating uncertainty after a verb such as ask, doubt, know, learn, or see:
在非正式的寫作中，可以使用if 或 wether 兩個詞來表達不定性，兩者都算標準，例如 ask,doubt,know,learn, 或 see這樣的動詞後：
We shall soon learn whether (or if ) it is true.
我們很快就會知道這是否（或 if ) 是真實的。
(2)In such contexts, however, the use of if can sometimes create ambiguities. Depending on the intended meaning, the sentence Let her know if she is invited might be better paraphrased as Let her know whether she is invited or If she is invited, let her know. · In conditional sentences the clause introduced by if may contain either a past subjunctive verb (if I were going ) or an indicative verb ( if I am going; if I was going ), depending on the intended meaning. According to the traditional rule, the subjunctive should be used to describe an occurrence that is presupposed to be contrary to fact, as in if I were ten years younger or if Napoleon had won at Waterloo. The main verb of such a sentence must then contain the modal verb would or (less frequently) should:
不過在這種情況下，用if 就可能會造成歧義。 Let her know if she is invited 這句話最好根據所要表達的意思， 分開說成告訴她她是否被邀請了 或 如果她被邀請了，就讓她知道 兩句話。 用if 引起的條件狀語從句中， 可以含有一個過去式的虛擬動詞(倘若我去 )或一個一般陳述動詞( 如果我就去；如果我去了 )， 這得依據所要表達的意思而定。根據正統的原則，虛擬語氣用來表達一個與事實相反的假設，例如如果我再年輕十歲 或者 如果拿破侖在滑鐵盧戰役中獲勝。 於是在這樣的句子裡，主要動詞必須包含情態動詞會 或（在較少情況下） 應該：
If America were still a British colony,
如果美國現在還是英國的殖民地，
(3)we would have an anthem that human voices could sing.
我們就會有一支人人都會唱的國歌。
If I were the President,
如果我是總統，
(4)I should (or would ) declare November 1 a national holiday. When the situation described by the if clause is not presupposed to be false, however, that clause must contain an indicative verb, and the choice of verb in the main clause will depend on the intended meaning:
我就（或 會 ) 宣佈十一月一日為國家休假日。 而只要if 引起的從句描述的條件不是事先就被認為是不可能的， 從句中就必須使用直陳動詞，而主句中詞的形式就要依所要表達的意義而定：
If Hamlet was really written by Marlowe, as many have argued, then we have underestimated Marlowe's genius.
如果就像很多人猜測的那樣，《哈姆雷特》一劇是由馬洛寫的，那我們就一直低估了馬洛的才能。
If Kevin was out all day, then it makes sense that he couldn't answer the phone.
如果確實一直在外面，打電話找不著他是很正常的。
(5)Note also that the presence of the modal verb would in the main clause should not be taken as a sign that the verb in the if clause must be in the subjunctive, if the content of that clause is not presupposed to be false:
另須注意，在主句中使用情態動詞would 並不表明 if 從句中一定使用虛擬語氣，因為從句的內容並不一定原先就認為是錯誤的：
If I was (not were ) to accept their offer—which I'm still considering—I would have to start the new job on May 2.
如果我去（不是 were ) 接受他們的盛情——我還在這樣考慮——那麼我必須在5月2日開始新工作。
He would always call her from the office if he was (not were ) going to be late for dinner. ·
如果他（不是 were ) 晚餐會遲到，就會從辦公室打電話給她。 ·
(6)Again according to the traditional rule, the subjunctive is not correctly used following verbs such as ask or wonder in if clauses that express indirect questions, even if the content of the question is presumed to be contrary to fact:
另外還是根據傳統規則，在動詞ask 或 wonder 中 if 引導的間接問句， 即使其內容被認為與事實相反，也不能使用虛擬語氣：
We wondered if dinner was (not were ) included in the room price.
我們想知道晚餐費用是否被（不是 were ) 包括在房間費中。
Some of the people we met even asked us if California was (not were ) an island. ·
我們碰到的一些人甚至問我們加利福尼亞是否是（不用 were ) 一個島嶼。
(7)With all deference to the traditional rules governing the use of the subjunctive, it should be noted that a survey of the prose of reputable writers over the past 200 years would reveal a persistent tendency to use the indicative was where the traditional rule would require the subjunctive were. A sentence beginning If I was the only boy in the world, while not strictly correct, is wholly unremarkable. But the corresponding practice of using the subjunctive in place of the indicative may be labeled a hypercorrection. · In spoken English there is a growing tendency to use would have in place of the subjunctive in contrary-to-fact clauses, as in if I would have been the President, but this usage is still widely considered incorrect.See Usage Note at doubt, should, wish
在與指導虛擬語氣使用方法的傳統規則相衝突的一系列不同用法中，我們應注意到一項對過去200年散文作家的調查顯示，在傳統語法要求使用虛擬式的were 的情況下，有一種持久的使用直陳式 was 的趨勢。 一句用假如我是世界上唯一的男孩 開頭的句子不會引起人們的注意。 而一定要把其中的直陳式換成虛擬式就顯得矯正過了頭。在英語口語中，在與事實相反的從句中，使用would have 一詞的趨勢有所增加， 例如如果我會是總統， 但這種用法仍然被大多數人認為是不正確的參見 doubt， should， wish
基本詞義
IF
IF 或 i.f.
abbr.（略語）
Intermediate frequency.
中波
現代英漢詞典
if
[If]
conj.
(1)如果；假如
If you ask him, he will help you.
如果你向他請求，他會幫助你。
"If need be, we'll work all night."
"如果需要,我們就干個通宵。"
(2)即使；雖然
We'll go even if it rains.
即使下雨我們也要去。
(3)是否
She asked if that was enough.
她問那是否夠了。
He asked if Mr Gilbert's operation had been successful and the doctor told him that it had been.
"他問吉爾伯特先生的手術是否成功,醫生告訴他,手術是成功的。"
詞性變化
if
n.
條件，限制條件
I don't want any ifs and buts; do it at once.
"我不想聽任何要推延的理由,立刻干吧。"
Your investigation report seems to have too many ifs.
你的調查報告似乎假設太多了一些。
現代英漢綜合大辭典
if
[if]
conj.
(1)[表示條件, 假設]如果, 要是; 假如
(2)[表示讓步]雖然; 即使
(3)是否, 是不是
(4)(＝whenever)無論何時; 當
(5)[表示願望, 感歎]要是....多好
If weather permits....
(常略作Ｉ.Ｗ.Ｐ)如果天氣好的話....
I'll do it if I die in the attempt.
即使會喪命我也要試一下。
Ask if he is at home.
問一問他在不在家。
If I do not understand what he says, I always ask him.
我不懂他的話時, 總是去問他。
If I haven't lost my watch!
我的表要是不丟該多好!
If I only knew!
要是我知道該多好。
詞性變化
if
[if]
n.
條件; 設想
ifs and buts
拖延的原因
Your argument seems to have too many ifs.
你的論據似乎假設太多了一些。
I don't want ifs and buts; swallow your medicine at once.
我可不聽你泡蘑菇, 馬上吞下你的藥。
習慣用語
if and when
如果, 萬一
If ifs and ans were pots and pans, there'd be no trade for tinkers.
[諺]如果種種「假如」能夠變成深鍋和淺鍋, 補鍋匠就沒有生意了。(意思是:如果人們的主觀願望都能實現, 天下就太平了)
if only
只要; 要是....就好, 但願
基本詞義
IF
(1)=Information Collector 信息收集器;
(2)Information Feedback 信息反饋;
(3)Intermediate Frequency 中頻;
(4)Institute of Fuel 燃料學會[英]
用法詞典
if