if僅由兩個(gè)字母組成，是一個(gè)看上去很簡(jiǎn)單的單詞，但是實(shí)際它的意思和用法都是很多的，那么接下來(lái)就來(lái)跟大家說(shuō)一說(shuō)if究竟包含有哪些意思。

簡(jiǎn)要回答

if是一個(gè)英語(yǔ)單詞，既可以作名詞又可以作連詞，作名詞意為不確定的情況，作連詞意為如果、假若、倘若、當(dāng)、無(wú)論何時(shí)、每次，與will或would連用，表示客氣地請(qǐng)求。

詳細(xì)內(nèi)容

if
英 [?f] 美 [?f]
conj.如果;假若;倘若;當(dāng);無(wú)論何時(shí);每次;與will或would連用，表示客氣地請(qǐng)求
n.不確定的情況
復(fù)數(shù)： ifs

語(yǔ)法說(shuō)明
【if】【whether】
Both if and whether are used in reporting questions which expect ‘yes’ or ‘no’ as the answer if和whether均用于要求以yes或no作答的轉(zhuǎn)述疑問(wèn)句中：
She asked if/whether I wanted a drink.
她問(wèn)我要不要喝點(diǎn)什么。
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. 不過(guò)whether與discuss、consider和decide等動(dòng)詞連用聽(tīng)起來(lái)更自然。提供選擇時(shí)用if或whether均可：
We didn’t know if/whether we should write or phone.
我們不知道是寫(xiě)信好還是打電話好。
In this last type of sentence, whether is usually considered more formal and more suitable for written English. 在最后這一句型中，一般認(rèn)為whether較正式，更適用于書(shū)面英語(yǔ)。

雙語(yǔ)例句
She gets very upset if I exclude her from anything
要是有什么事情我不讓她參加，她會(huì)非常難過(guò)。
He asked if I had left with you, and I said no
他問(wèn)我是否和你一塊兒離開(kāi)的，我說(shuō)不是。
Sometimes, that standard is quite difficult, if not impossible, to achieve
有時(shí)即便有可能達(dá)到那個(gè)標(biāo)準(zhǔn)，那也是非常困難。
If I could just make another small point about the weightlifters in the Olympics
請(qǐng)?jiān)试S我就有關(guān)奧運(yùn)會(huì)舉重運(yùn)動(dòng)員的問(wèn)題再補(bǔ)充一點(diǎn)。
I wonder if you'd be kind enough to give us some information, please?
請(qǐng)問(wèn)您能不能給我們提供一些信息？
If there was any disappointment it was probably temporary
即便有點(diǎn)兒失望，也肯定是暫時(shí)的。