赵秀卿
摘 要:在英语学习过程中,熟知各种基本句式至关重要,但常有学生在做句型转换时,分不清楚什么时候用be动词,什么时候用助动词do,does,did,什么时候用情态动词can,may,must,更因辨别不清have/has/had,need等是助动词还是实意动词,导致错误百出,失分较多。教给学生一招实用性较强的小技巧,使学生轻松地掌握基本句式。
关键词:英语;教学;语法
为方便记忆,我将所有的动词分为两大类,我们姑且称之为:一类词和二类词。一类词包括be动词、助动词和情态动词。二类词包括所有的实意动词和除be之外的系动词。
总的来说,所有的句型转换,无论是否定句、疑问句、反问句还是省略、替代,我们都要借助于一类词。下面我们就详细划分一下。
一、一类词
(一)一类词可分为以下三种
1.be动词:am,is,are,was,were;
2.助动词:do,does,did,have,has,had;
3.情态动词:can,may,must,should,could,would,need,shall,will,would。
(二)基本原则
1.肯定句变否定句时,在充当谓语或谓语一部分的一类词后直接加not,即主语+一类词+not+其他。注意有一变:即将原句的some变成any。
例如:He is good at playing basketball.
否定句:He isnt good at playing basketball.
Were listening to English now.
否定句:We are not listening to English now.
2.肯定句变一般疑问句时,直接将一类词提前,放在句首,即一类词+主语+其他,注意有两变:除了将原句的some变成any,还要将第一人称与第二人称相互转换。用哪种一类词提问就用哪种疑问词来回答,当然还要考虑与主语人称、单复数保持一致。
例如:He is good at playing basketball.
一般疑问句:Is he good at playing basketball?Yes, he is. / No, he isnt.
Were listening to English now.
一般疑问句:Are you listening to English now?Yes, we are. / No, we arent.
3.肯定句变特殊疑问句时,就在一般疑问句形式前加特殊疑问词,即特殊疑问词Who/Whom/What/When/Where/How等+一类词+主语+其他。注意有三变:将原句的some变成any,将第一人称与第二人称相互转换,原句画线提问若包括谓语动词,则谓语动词根据原句用do,doing或done来代替。
例如: We have seen that movie before.
否定句:We havent seen that movie before.
一般疑问句:Have you seen that movie before?Yes, we have./No, we havent.
特殊疑问句:What have you done?
4.变反意疑问句时,反问部分结构:一类词的肯定或否定+原句主语的代词形式。
例如: We have seen that movie before.
反义疑问句:We have seen that movie before, havent we?
The students are playing football on the playground, arent they?
5.省略和替代时,前文出现哪种一类词,省略和替代就用哪种一类词,当然还要考虑与主语人称、单复数保持一致。
例如:Mary is good at playing the piano.—— So she is.(她确实如此。)
Mary is good at playing the piano.——So am I.(我也是)
(三)注意事项
1.be动词后绝对不能加动词原形,要想接动词,只能加动词的三种非谓语形式:动词的现在分词V-ing、动词的过去分词V-ed形式或 to do不定式。
2.助动词本身无意义,不能单独做谓语,当句中谓语有了助动词do/does/did,无论是肯定形式还是否定形式,其后一定接动词原形,但不能接be动词。当句中有了助动词have/has/had,无论是肯定还是否定,其后一定接动词的过去分词形式。
3.情态动词没有人称单复数的变化,只能用其本身或过去式,并且情态动词不能单独做谓语,其后必须加动词原形,可以接be动词。
4.have/has/had只有在接動词的过去分词V-ed时,才是助动词,其变化借助于自身;其余情况应视为实意动词,变化借助于助动词的do/does/did。
例1:We have made much progress. 此时,have为一类词。
否定:We havent made much progress.
疑问:Have you made much progress?Yes, we have. /No,we havent.
例2:He has two sisters.此时,has为二类词。
否定:He doesnt have two sisters.
疑问: Does he have two sisters?Yes, he does. / No, he doesnt.
5.need当情态动词时,只能用原形,其后必须接动词原形,各种变化应借助于need自身;need当实意动词时,有了人称单复数和时态的变化,其后可接名词、to-do不定式,其否定、疑问、反问都应借助于助动词do/does/did。
例1:we need learn English well.此时,need为情态动词,属于一类词。
否定:We neednt learn English well.
疑问:Need you learn English well?Yes, we must./ No,we neednt.
二、二类词
(一)定义
二类词包括所有的实意动词和除be动词之外的连系动词。当句中谓语是二类词时,无论是否定句、疑问句还是反问句,我们都要借助于一类词中的助动词do/does/did。究竟应借助助动词中的do、does还是did,一要看原句时态,二要看原句主语单复数。一定要牢记的是:只要借助于助动词do/does/did,原句中的謂语动词一定要改为原形!
(二)基本原则
1.否定句结构:主语+dont/doesnt/didnt +动词原形+其他。
2.一般疑问句结构:Do/does/did +主语+动词原形+其他?
3.特殊疑问句结构:特殊疑问词+do/does/did+主语+其他?
例1:He did his homework well yesterday. 此时,did为二类词。
否定句:He didnt do his homework well yesterday.
一般疑问句:Did he do his homework well yesterday?
特殊疑问句:How did he do his homework yesterday?
反问句:He did do his homework well yesterday, didnt he?
综上所述,这是我在多年实际教学中针对学生常见错误总结出来的一点经验。当然,空有理论,只是纸上谈兵,这就需要我们在具体运用中,去摸索、去发现、去求实,以达到熟练掌握、真正为我所用的程度。
编辑 马晓荣