浅谈it用法的教学实践

2018-06-20 09:32葛玉英
关键词:口诀公式

葛玉英

摘 要:it在英语中应用广泛,是高考的重要考点之一。掌握其用法并能灵活运用是教学的重点和难点。让学生在教学中用熟记口诀和公式的方法逐一准确把握其用法规则,最终达到熟练掌握应用的目的。

关键词:it的用法;口诀;公式

中图分类号:G633.41 文献标识码:A 文章编号:1009-010X(2018)14-0011-05

It在英语中使用广泛,用法繁杂多变,是近几年高考命题的热点,同时也是日常教与学的重点和难点。尤其是it用法中一些近似句型的辨析,常使学生望而却步。通过课堂教学实验,笔者认为学好it用法,可通过记忆口诀和公式的方法强记一些特殊的用法,让凌乱的内容有条理起来,从而大大激发学生的兴趣、记忆深刻。这样以点代面、逐步拓宽、逐层深入、逐步完善,最终达到全面掌握、熟练应用的目的,在教学中能收到事半功倍的效果。

讲解it的用法可从五个大的方面入手:1.掌握it作代词的基本用法;2.熟练it作形式主语的用法;3.熟练it作形式宾语的用法;4.牢记it引导的强调句;5.熟记 it引导的时间句型。

一、It做代词的用法有三种

(一)It可代动物、婴儿和未确定身份的人

某人指着小狗说:It's lovely.(it指dog)。指着刚出生的婴儿说:It weighs 3 kilos.(it指baby)。陌生人敲门时屋内人常说:Who is it?(it指屋外人) ——It's Tom/me.(屋外人自指)。

(二)It代替指示代词this和that,及上文提到的事物

某人指着图片说:What's this/that? It's our school.(it指this/that)。

It's very beautiful.(it指our school)。

(三)It可指代金钱、距离、天气、时间、环境等

(1)I have 100 million, it is a great deal of money.(it指100 million)。

(2)The Great Wall is more than 6700 kilometers long. It is a long way.(it指more than 6700 kilometers的距离)。

(3)It is windy and snowy.(it指weather)。

(4)It was midnight when she came back.(it指time)。

(5)It was very quiet in the village.(it指circumstance)。

(6)It doesn't matter./It is a shame.(it指something)。

以上三种情况明显得知:it可代可数名词单数、复数和不可数名词。一般现在时中谓语动词对应用动词的第三人称单数。由此可见,学好it的用法对于主谓一致的语法学习关系密切。

It作代词的用法,可以用口诀熟記:It指代要牢记,性别不明和baby,天时距金这那事(天气、时间、距离、金钱、这个、那个、事物)。这样学生通过联想记忆,应用效果好。

二、It作形式主语

众所周知,有些主语放在句首时主句整体结构有些头重脚轻,it是用来改善句子平衡的。用it代替不定式短语、动名词短语和从句做主语,而真正主语放句尾。It是第三人称单数,一般现在时谓语动词用动词第三人称单数。

学习it做形式主语时,可以重点先让学生掌握it作形式主语的几个常见公式:

1.It takes sb. some time/some money to do sth.(做某事用了某人多少时间/多钱。it代to do sth.)。

如:It took me one hour to finish my homework.完成家庭作业用了我一小时。

2.It is + adj.+ of/for sb.+ to do sth.(it代to do sth.,形容词adj.指的是sb.的性格、特点、品质等表示情感态度的词。如:good, bad,careful, careless, polite, impolite, kind, cruel等, 用介词of,而for与情感态度无关)。

如:It's very nice of you to help me.(nice是you的性格特点,故用of)。

It's very important for us to learn English.(important与人的性格特点无关,故用for)。

Is _____ possible ______ us to finish the work in such a short time?

A.it, of B.it, for C. that, of D. that, for

(形式主语用it,形容词 possible不表达某人的性格特点,故选B)

3.It is useless to do sth.= It is of no use to do sth.

如:It is useless to say sorry. = It is of no use to say sorry.(说道歉无用)。

4.It's+ no good/ no use/ a waste of time + doing sth.(做某事没用/没好处/浪费时间。it指doing sth.)。

如:It's no good____, you'd better give it up.

A.to smoke B.smoking C.smokes D.smoke

(根据公式,选B)

5.It + is + V过去分词 + that…从句.(常见动词有:report, say, believe, think等,据报道/据说/被相信/被认为……)。

如:It is ________ chairman Xi has visited Russia(俄国)successfully.

A.report, that B.reported, that

C.report, which D.reported, which

(根据公式,选B)

6.It is suggested (requested, proposed, desired, etc.) that…从句。

动词是insist(1.坚持),order ,command (2.命令),advise, propose, suggest(3.建议),demand, request, require ,desire (4.要求)等,that主语从句中谓语动词要用 (should) +V原,should可略。

It is suggested that we _____ a holiday.

A. had B. have C. have had D. will have

(建议我们应该有一个假期。故选B)

7.It is important(necessary, strange, natural, right) that…从句.(that引导的主语从句用来表示说话人的建议、忠告、意见、命令等情感。从句谓语要用虚拟语气should +V原,should可略)。

如:It is necessary that you ______ English words first.

A. remember B. would remember

C. to remember D. is remembering

(必要的是你们应该先背单词。此句表达的是说话人的忠告,故选A)

8.It is a pity/no wonder/wish/+that…从句.(从句中谓语应为should +V原,should可略)。

It is a pity that we_____ the chance to get the job.

A. lost B. lose C. would lose D. is losing

(遗憾的是我们竟然失去得到那份工作的机会。故选B)

如果先让学生记住这几个公式,在运用中逐步理解,it作形式主语的用法就基本清晰了。

三、It作形式宾语

(一)若谓语动词think, suppose,consider, find, feel, make, believe等后面接賓补时,这些动词后常接it作形式宾语,而真正的宾语置于句尾

结构:主语+谓语+it+宾补+真正宾语

此结构可细化为公式: 主+ feel/think/ find/ consider/ make/ believe /suppose+ it + adj./n.+ to do sth./doing sth./从句。

记忆这7个谓语动词时,我们可以想象为解决一件事情出谋划策:我认为/猜测(think/suppose),先考虑(consider),找感觉(find,feel), 使相信(made,believe)。从而有效地记忆这些谓语动词。此结构的宾补词性有2种,即名词和形容词。真正宾语为动词不定式、动名词和从句3种形式,所以我们常常把此句型称之为7123结构。

(1)She thinks ____ easy ____ two foreign languages for her.

A.that, to master B.that, mastering

C.it, to master D.it, mastering

(根据公式,选C)

(2)The manager didn't feel like___ whether he would attend the meeting the next morning.

A.making it clear B.make it clear

C.to make it clear D.making this clearing.

(这道题用到两种语法,一是想要做某事用feel like doing,二是形式宾语的句型7123结构,故选A)用这一结构特征学生学习兴趣浓、记忆牢固且不易出错。

(二)某些及物动词和动词短语后接宾语从句时,需先加it,再加从句

常见的结构有以下几种:

1.主+动词+it+if/when…从句

I dislike it when people talk with their mouths full.

(我不喜欢人们带有满嘴食物交谈。)

I'd appreciate it if she could help me with my English.

(如果她能在英语方面帮助我,我会很感激。)

此类动词常为表喜、怒、哀、乐的词:enjoy, like,dislike,hate,appreciate 等。

2.主+动词+it+that…从句

The father takes it that his son can deal with the thing by himself.

(那位父亲认为他的儿子能靠自己处理那件事。)

Report has it that a farmer found a wonder under the earth.

(有传言一个农民发现一个地下奇迹。)

此结构动词非常少,如:take it that… 认为……假定……猜想;have it that…认为……据闻……传言; like it that… 很高兴……很喜欢; put it that… 理解为……可以说是……

3.主+动词+it+介词词组+that…从句

I owe it to my teacher that I have made progress.

(我取得的进步,多亏我的老师。)

Don't take it for granted that parents will give you money.

(不要认为父母亲给你钱是理所当然的。)

常见的固定搭配有: take it for granted 认为……理所当然,想当然……; keep it in mind 把……牢记;bring it to sb.'s attention 使某人注意……;owe it to sb. ……归功于某人,……多亏了某人;leave it to sb. 把……留给/委托某人。

4.主+动词+介词+it+that…从句

Parents are counting on it that I will go to a good university.

(父母亲正盼望我上一所好大学。)

You'll see to it that you can finish the homework on time.

(你将务必按时完成家庭作业。)

常见动词词组有:see to务必,注意;look to注意,当心;insist on堅持,主张;stick to坚持,忠于;depend on 依靠,相信;answer for保证,负责;count on依靠,期望。

It作形式宾语虽然较繁杂,但如果我们把它归纳为:一种结构(7123)和4个公式,学生学得既快又准,能吸引学生兴趣。

四、It做引导词引导的强调句

常见句型1. It is/was+被强调的部分+that/who/whom+其他成分。

首先,让学生明白两点。第一,原句谓语动词的时态是现在范畴(一般现在、一般将来、现在进行、现在完成等)用it is ;原句谓语动词的时态是过去范畴(一般过去、过去将来、过去进行、过去完成等)用it was。第二,此结构只限于强调主语、宾语和状语。

注意事项有三点:1.如果强调的是人,连接词用that或who, whom(只强调宾语),强调的是物只用that;2.如果强调时间、地点、原因时应注意与定语从句区别,在强调句中只能用that连接,不能用when, where, why;3.强调句中如果把句型结构划掉后,应该是一个完整无缺的句子。

如:I met Tom in the street yesterday.

It was in the street that I met Tom yesterday. (强调状语)

It was I that (who) met Tom in the street yesterday.(强调主语)

如:(1)It was in Xi'an ______ the young couple met for the first time last year.

A. where B. what C. when D. that

(去掉句型结构是一个完整句子,故选D)

(2)It is the school ____ I went to college.

A. where B. what C. when D. that

(去掉句型结构不是一个完整句子,所以此句是一个定语从句,故选A)

此外,高考中还常考查强调句中的以下几点:

1.如果被强调的部分是主语,that/who后的其他部分的动词应和被强调部分(即主语)人称和数保持一致。

(1)It is he who helps me.

(2)It was what she did that encouraged me.她所做的鼓励了我。

2.如果是特殊疑问句的强调句,疑问词应置于句首,后跟一般疑问句语序。其句型为:疑问词+is/was+it+that+剩余部分+?

(1)When was it that you met Tom at the school gate ?

(2)What was it that made you change your idea ?

3.如果特殊疑问句的强调句出现在宾语从句中,注意其结构为陈述语序。句式为:

疑问词+it+is/was+that+剩余部分。

(1)I can't remember when it was that he arrived in Shanghai.

(2)I don't know what it was that makes him so happy.

常见句型2. It is/was not until+被强调部分+that+其他成分。

注:译为“直到……时候,才……”强调句中否定前移,that后必须用肯定形式。

如:He did not come back until twelve o'clock.

强调句:It was not until twelve o'clock that he came back.

如: It was not ____ I read the poem recently ____ I really appreciated its beauty.

A. when, that B. until, that

C. until, when D. when, when

(直到我最近读那首诗,我才真正欣赏到它的优美之处。根据句型结构选B)

总之,学习it引导的强调句时,如果熟练掌握这两种句型结构并加以实际运用,定能收到良好的效果。

五、It引导的时间句型

(一)It与time连用的句型

1.It is (about/high) time that…从句(从句用一般过去时或should+ V原,should不能省)。该到某人做某事的时候了。

2.It is/was the +序数词+time+that…从句(从句用现在完成时/过去完成时)。

注:主句谓语是is,从句谓语用has+V过分;主句谓语是was,从句谓语用had+V过分。这是某人第几次做某事了。

如:It is time that children _____ to bed.

A.go B.went C.gone D.going

(该到孩子们睡觉时间了。故选B)

(二)It与since连用的句型

1.It is/has been+时间段+since…从句 (从句用过去时)。

注:如果since从句谓语动词是瞬间动词,译为“自从这个动作开始起”;如果since从句谓语动词是延续动词,译为“自从这个动作结束起”。

2.It was some time since sb. had done sth.

两个句式都译为:自从……以来,已经多长时间了。

It is/has been 20 years since I came here.(自从我来这,已经20年了)

He said it was five years since he had come back.(他说自从他返回,已经五年了。)

(三)It与before连用的句型

1.It + will/may be + 一段时间 + before…从句(一般现在时)。“要/也许过一段时间,才……”。

2.It will not be + long + before…从句(一般现在时)。“用不了多久,就……”。

例:It will be five weeks before she comes back.(再过五个星期她才回来。)

3.It was + 一段时间 + before…从句(过去时)。“过了一段时间,才……”。

4.It was not + long + before…从句(过去时)。“用不了多久,就……”。

如:It was two months _____ I finished reading the book.

A. since B. until C. when D. before

(我用两个月才读完那本书。故选D)

It wasn't long before they felt regret.(不久他们就会后悔了。)

(四)It 与when 连用的句型

It + be + 具体时间 + when + 从句(时间前无介词,主从句谓语动词时态一致)。

例:It was already late afternoon when we finished our work.(主过從过)我们完成工作时已经傍晚了。

熟记it引导的时间句型,学生做题变得更加容易方便。

此外,还有it的习惯用语,如:

Take it easy.不要慌, 别担心;It all depends./That all depends.那要视情况而定; It's up to sb.这取决于某人;Don't mention it.别提了;Believe it or not.信不信由你;It doesn't matter.没关系;Make it.说定、成功、做到、赶上;As it is.事实上,实际情况,照原样。

有关it的谚语,如:

(1)It is never too late to learn.活到老,学到老。

(2)It's no use crying over spilt milk.覆水难收。

(3)Strike the iron while it is hot.趁热打铁。

在日常生活中,有关it的固定搭配、习惯用语及谚语有许多,让学生边搜集、边总结、边记忆,一定能丰富it用法的内容,拓展知识面。

最后,把it用法总结归纳为口诀:小小代词本领大,即可指这又指那,时间天气均可指,谈到距离也用它,形主形宾均可做,强调句型及固搭。笔者相信,通过记忆口诀和常用公式,学生一定对it的用法有一个全面的了解掌握,能胸有成竹地应对每一道题。

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