所謂存在句，就是指表示某處存在有某人或某物的一類句型，這類句型的典型結(jié)構(gòu)是there be…這類表達(dá)，所以存在句在通常情況下指的就是there be句型。如：

There is a garden at the back of the house.

there be句型中的there為引導(dǎo)詞，無詞義；be為謂語動(dòng)詞，根據(jù)情況可以有單復(fù)數(shù)的變化，也可以有不同的時(shí)態(tài)變化;there be后面的名詞為句子主語。表示某處存在有某人或某物是存在句最基本的用法，在實(shí)際運(yùn)用中，它可以有更廣的用法。如：

There are not enough people to do the job.

There are a lot of things I’d like to ask you.

這些個(gè)句子中的there be句型并不具體表明某處存在有某事物，可視為there be句型基本結(jié)構(gòu)的延伸用法。

主謂一致：若there be只有一個(gè)主語，謂語的數(shù)則取決于該主語的數(shù);若有幾個(gè)主語并列，則通常是與靠近的主語保持一致。如：

There is a bus stop close to the school.

但是，在非正式場(chǎng)合，there’s 往往可以用來代替復(fù)數(shù)形式there are 用于復(fù)數(shù)名詞前。如：

There’s lots of cars on the road these days.

時(shí)態(tài)問題：there be結(jié)構(gòu)的時(shí)態(tài)由其中的謂語動(dòng)詞be來體現(xiàn)，它可以有一般現(xiàn)在時(shí)、一般將來時(shí)、一般過去時(shí)、現(xiàn)在完成時(shí)、過去完成時(shí)、過去將來時(shí)多種時(shí)態(tài)形式。如：

There is nothing to be done now.

There’s going to be trouble.

There wasn’t any change in him.

There have been many such accidents.

There had been many such occasions.

There would be endless rows if I was at home.

連用情態(tài)動(dòng)詞：there be結(jié)構(gòu)有時(shí)可以與情態(tài)動(dòng)詞can / could 、may / might、must、should、ought to 、used to 連用，此時(shí)情態(tài)動(dòng)詞應(yīng)放在there與be之間。如：

There must be a mistake.

there be的變體：有時(shí)根據(jù)句子的需要，我們也可將there be中的動(dòng)詞be 換為 live, remain, seem, appear, exist, stand, lie, come等。如：

There comes a bus.

否定式：there be結(jié)構(gòu)的否定式通常應(yīng)將否定詞置于動(dòng)詞be之后。如：

There is not any bread left.

若謂語中包括有助動(dòng)詞或情態(tài)動(dòng)詞，通常將否定詞置于助動(dòng)詞與情態(tài)動(dòng)詞之后。如：

There can’t be so many mistakes.

疑問式：there be結(jié)構(gòu)的疑問式通常應(yīng)將否定詞置于動(dòng)詞be之后。如：

Is there any good film on?

若謂語中包括有助動(dòng)詞或情態(tài)動(dòng)詞，通常將助動(dòng)詞或情態(tài)動(dòng)詞移至句首構(gòu)成疑問式。如：

Has there been an accident?

there be結(jié)構(gòu)的非謂語形式有兩種，即there being和there to be。

there being結(jié)構(gòu)：該結(jié)構(gòu)在句子中主要用作狀語。如：

There being nothing to do, I went to bed.

這類結(jié)構(gòu)有時(shí)可與狀語從句轉(zhuǎn)換，如上句也可作如下改寫：

As there was nothing to do, I went to bed.

另外，there being結(jié)構(gòu)還可用作介詞賓語。如：

What’s the chance of there being an election this year?

there to be 結(jié)構(gòu)：主要用作動(dòng)詞賓語?？山釉摻Y(jié)構(gòu)可用作動(dòng)詞的動(dòng)詞不多，常見的like, prefer, hate, want, mean, intend, expect, consider等。如：

I don’t want there to be any more trouble.

注意，在let there be結(jié)構(gòu)中，動(dòng)詞be不帶to。如：

Let there be no mistake about it.

另外，there to be 結(jié)構(gòu)還可用作介詞for的賓語。注意了，用作介詞賓語一般用there being，但用作介詞for的賓語時(shí)，卻要用there to be。比較：

It was too late for there to be any buses.

They asked for there to be another meeting.

there be+賓語+現(xiàn)在分詞：現(xiàn)在分詞表示主動(dòng)關(guān)系，同時(shí)表示動(dòng)作正在進(jìn)行。如：

There is someone waiting for him.

有時(shí)現(xiàn)在分詞不表示動(dòng)作在進(jìn)行，而表示一種狀態(tài)或現(xiàn)狀。如：

There’s a piano standing against the wall.

正如come, go, leave, move 等表示位置移動(dòng)的短暫性動(dòng)詞的進(jìn)行時(shí)態(tài)可表示將來意義一樣，“there be+名詞+現(xiàn)在分詞”也可以表示將來意義。如：

There are ten people coming to dinner.

there be+賓語+過去分詞：過去分詞表示一種被動(dòng)關(guān)系，同時(shí)表示動(dòng)作已經(jīng)發(fā)生。如：

There was nobody injured.

有時(shí)過去分詞也可表示一種狀態(tài)(可轉(zhuǎn)換成被動(dòng)結(jié)構(gòu))。如：

There were some old men seated (=who were seated) in the back.

there be+賓語+不定式：不定式通常表示動(dòng)作尚未發(fā)生。如：

There was nobody to look after the child.

當(dāng)其中的賓語與其后的不定式為被動(dòng)關(guān)系時(shí)，可用主動(dòng)表被動(dòng)，也可用被動(dòng)式。如：

There is much work to do [to be done].

但有時(shí)含義有差別——不定式用主動(dòng)式可視為其前省略了for sb，用被動(dòng)式可視為其后省略了by sb。如：

There is nothing to do. 無事可做。(含有無聊之意)

There is nothing to be done. 不能做什么了。(指沒有辦法了)

表示否定：此時(shí)表示“不可能……”“無法……”。如：

There is no getting over the difficulty.

表示不允許：此時(shí)表示“不許……”“不準(zhǔn)……”。如：

There is no photographing here.

名詞為difficulty：There is no difficulty in doing sth的意思是“做某事沒有困難”。如：

There is no difficulty in finding his office.

名詞為harm：There is no harm in doing sth的意思是“做某事沒有害處”。如：

There’s no harm in your coming early.

名詞為point：There is no point in doing sth的意思是“做某事沒有用或沒有必要”。如：

There’s no point in wasting time.

名詞為sense：There is no sense in doing sth的意思是“做某事沒有道理或好處”。如：

There’s no sense in criticizing him.

名詞為use：There is no use in doing sth的意思是“做某事沒有用或好處”。如：

There is no use in trying to help him.