Part 2 语言表达高分进阶
1．萌芽期：15~20分必会语法点
很多独立写作拿limited的考生，通常情况下其语法错误会非常多，一些基本的写作习惯、词汇使用、句子结构等使用并不规范。笔者在这里整理了词汇、词性、句子、特殊句式等几个方面的语法错误，希望能够帮助基础段考生（托福写作在15分及以下分数的考生）规范语法使用，减少语言错误。
（1）词的错误
1）拼写错误
总是有部分考生对某些词汇的拼写记忆不清、混淆严重。例如，argue的名词是argument，judge的名词是judgment，argument和augment混淆，contend和content混淆等。如：
【错误】The professor in the lecture contents that this method is not fair and economically competitive at all.
【正确】The professor in the lecture contends that this method is neither fair nor economically competitive at all.
其他易混词汇，考生可参考《常见拼写易错单词表》。
2）名词
名词的可数不可数问题容易被考生忽略，这是因为在汉语中并不区分名词是否可数。受这种思维习惯的影响，考生往往不注意哪些量词只能修饰可数名词，而哪些只能修饰不可数名词。如，修饰可数名词的有：a number of, many, few, a few；修饰不可数的有：huge amounts of, a great deal of, little, a little；两个皆可修饰的有：some, any, a lot of, lots of, plenty of等。
另外，很多考生不注意可数名词的用法，可数名词前面没有形容词修饰时，需用a/an或the来修饰，或者用名词复数。所以考生可以说I would like an apple.或特定情况下说I like the apple.或者可以说I like apples。但是不能说I like apple。
【错误】So the advices and ideas from whatever entertainers or famous athletes as long as people who are succeed are worthy listening and have great help.
【解析】advice表示“建议”，是不可数名词，所以没有复数形式，应改为advice。此外，该句也出现了后面要介绍的语法错误：双谓语。
【正确】So the advice and ideas from whichever entertainers or famous athletes, as long as people who have succeeded, are worth listening to and are helpful.
【错误】There was a considerably growth in the amount of people becoming UK citizens according to the report.
【解析】the amount of只能修饰不可数名词，而people是可数名词，所以不能用the amount of来修饰people，而应该改为the number of。
【正确】There was considerable growth in the number of people becoming UK citizens according to the report.
3）代词
一部分考生在用代词时，也知道代词用来指代，但是指代却不明确。
【错误】By doing this, the quality of the work is well guaranteed.However, as for starting immediately, it can only check while doing.When there is a crucial mistake, it is too late for them to fix up and the quality of the project is discounted seriously.
【解析】第一个代词it用错。前面既没有需要被指代的名词，后面while doing的真正主语应该是people，主从句的主语一致时，才可以省略从句中的主语（见状语从句的省略）。这里有了明确的名词people，后面的them也有了需要指代的对象；否则them也指代不明确。
【正确】By doing this, the quality of the work is well guaranteed.However, as for starting immediately, people can only check while doing.When there is a crucial mistake, it is too late for them to fix up and so the quality of the project is discounted seriously.
4）动词
动词的用法最多，也是考生最容易出错的地方。笔者仅列出部分常见错误，供考生备考时参考。
·后面接动词不定式（而不接动名词）做宾语的20个常用动词
afford to do sth.负担得起做某事
agree to do sth.同意做某事
arrange to do sth.安排做某事
choose to do sth.决定做某事
decide to do sth.决定做某事
demand to do sth.要求做某事
determine to do sth.决心做某事
expect to do sth.期待做某事
afraid to do sth.害怕做某事
help to do sth.帮助做某事
hope to do sth.希望做某事
learn to do sth.学习做某事
manage to do sth.设法做某事
offer to do sth.主动提出做某事
plan to do sth.计划做某事
prepare to do sth.准备做某事
pretend to do sth.假装做某事
promise to do sth.答应做某事
refuse to do sth.拒绝做某事
want to do sth.想要做某事
·后面接动名词（而不接动词不定式）做宾语的26个常用动词
admit doing sth.承认做某事
advise doing sth.建议做某事
allow sb.doing sth.允许某人做某事
appreciate sb.doing sth.感激某人做某事
avoid doing sth.避免做某事
consider doing sth.考虑做某事
delay doing sth.推迟做某事
deny doing sth.否认做某事
dislike doing sth.不喜欢做某事
enjoy doing sth.喜爱做某事
escape doing sth.逃脱做某事
fancy doing sth.设想做某事
finish doing sth.完成做某事
forbid doing sth.禁止做某事
forgive doing sth.原谅做某事
give up doing sth.放弃做某事
keep doing sth.保持做某事
mind doing sth.介意做某事
permit doing sth.允许做某事
practice doing sth.练习做某事
prevent sb./sth.doing sth.阻止做某事
prohibit doing sth.禁止做某事
put off doing sth.推迟做某事
risk doing sth.冒险做某事
suggest doing sth.建议做某事
understand doing sth.理解做某事
【错误】As far as I am concerned, children shouldn't spend all their time to play and study, while doing household is very necessary for them.
【正确】As far as I am concerned, children shouldn't spend all their time playing and studying, while doing household is very necessary for them.
·动词时态。托福写作常用时态为一般现在时和一般过去时。独立写作中例子部分会经常涉及一般过去时；综合写作中也可能会用到一般过去时。考生需要足够重视。
5）情态动词
情态动词没有人称和数的变化；也不能单独使用，必须与其他动词一起构成谓语，后接动词原形。常用情态动词及其用法含义如下：
can（could）, may（might）, must, have to, shall（should）, will（would）, dare（dared）, need（needed）, ought to等。情态动词无人称和数的变化；不能单独使用，必须与其后的动词原形构成谓语。
6）介词短语
有时考生会把介词短语直接拿来当作主语使用，如：
【错误】In this way can also cultivate our planning ability when complete a big project which is the essential quality to have in society.
【解析】介词短语不能做主语，应该加上主语。另外，后面有when引导的状语从句，从句真正的主语是人，需要把主语加上。这也是本节后面要讲解的“缺主语”问题。
【正确】In this way, it can also cultivate our planning ability when we complete a big project which is the essential quality to have in society.
【错误】Under such pleasant mood will bring the motivation that makes everything even better and more pleasant.
【解析】该句谓语是will do，主语是under xxxx的介词短语，很明显语法不通。完全可以把under去掉。或者加上句子真正的主语。
【正确】Under such pleasant mood, we are equipped with motivation which makes everything even better and more pleasant.
此外，部分介词短语带to，这里的to是介词，因此后面不能接动词，应该用动词的-ing形式。此类用法总结如下：
①动词+介词to+动名词
admit to doing sth.承认做了某事
apply to doing sth.适用于做某事
object to doing sth.反对做某事
stick to doing sth.坚持做某事
②动词+宾语+介词to+动名词
apply oneself to doing sth.专心致力于做某事
reduce sb.to doing sth.使某人沦为做某事
devote oneself to doing sth.献身于做某事
limit somebody to doing sth.限制某人做某事
③动词+名词+介词to/towards/for+动名词
pay attention to doing sth.专注于做某事
set one's mind to doing sth.决心做某事
have a dislike towards doing sth.厌恶做某事
have an eye for doing sth.注意做某事
have an objection to doing sth.反对（反感）做某事
④be+形容词+介词to+动名词
be used to doing sth.习惯于做某事
be opposed to doing sth.反对做某事
be limited to doing sth.把……限制在做某事的范围内
be devoted to doing sth.把时间（钱、精力等）献给做某事
7）连词与副词的混淆。
副词在句子中做状语，修饰动词、形容词或其他副词。如果删去，句子仍然是一个完整的句子。如：He totally agrees with our suggestion.去掉totally，句子仍然完整。
连接副词，一类是用于连接句子或从句，常见的有therefore, besides, otherwise, however, moreover, still, thus, meanwhile等，在句中位置比较灵活。另一类是用于引导从句或动词不定式，主要有when, why, where, how等。如：She tries to figure out what she could do to save energy in her daily life.或She tries to figure out how to save energy in her daily life.
而when, where, why又叫作关系副词，引导定语从句。如：He illustrates the reason why the national fence does not work.
连词用来连接两个句子，这时两个句子是并列、因果、转折等关系，不存在主从关系。如果删去这个连词就变成两个完整的句子。英语中两个并列的分句之间必须有连词，否则就要分别点句号。
常用的英语连接词包括：
·表示承接的过渡词：also，and，and then，too，in addition，furthermore，moreover，what's more, again，on top of that，another，first，second，third等。
·表示时间顺序的过渡词：now，then，before，after，afterwards，earlier，later，immediately，soon，next，in a few days，gradually，suddenly，finally等。
·表示空间顺序的过渡词：near（to），far（from），in front of，behind，beside，beyond，above，below，to the right/left，around，outside等。
·表示比较的过渡词：in the same way，just like，just as等。
·表示转折的过渡词：but，still，yet，however，nevertheless，nonetheless，on the contrary，in spite of/in spite of the fact that，even though，although，despite /despite the fact that等。
·一方面，另一方面：on the one hand，on the other hand，for one thing，for another等。
·表示结果和原因的过渡词：because，since，so，as a result，therefore，then，furthermore，thus，otherwise等。（as a result,therefore, thus并不是连词而是介词，尤其是thus，虽然有连词的用法，但是不常用。）
·表示目的的过渡词：for this reason，for this purpose，so that等。
·表示强调的过渡词：in fact，indeed，surely，necessarily，certainly，without any doubt，truly，to repeat，above all，most important等。
·表示解释说明的过渡词：for example，in fact，in this case，for actually, for instance等。
【错误】Although it seems to begin earlier, but it ends later.I remember, last semester, my finance class professor asked us to hand in a financial position analyze of a specific company.
【解析】非常典型的语法错误，英语中“尽管”和“但是”不能连用，即although/though后面不能出现but，但是可以用yet。
【正确】Although it seems to begin earlier, it actually ends later.I remember, last semester, my finance class professor asked us to hand in a financial position analysis（analyze是动词，要改为analysis）of a specific company.
【错误】As so many people commenting on the Internet, there won't lack of the criticism of the expert from specialized viewpoint like the mechanism and efficiency of operating.
【正确】As so many people are commenting on the Internet, there won't be a lack of expert criticism from specialized viewpoints such as the mechanism and efficiency of operations.
改错练习
1．Since the fierce competition between the students, they pay much more attention on the final grades than the past.
2．As she searching on the Internet, she knew that it is because of the advanced functions on the computer which waste most of the battery and to overcome this shortcoming, she just needed to shut it off, and then the battery will last for a very long time.
3．From my point of view, people now are much happier or more satisfied than the past with their life as the society development.
4．Children begin to spend plenty of time face to the computer screen surfing the internet, playing video games as for fun and entertainment.Because they think it is very novel and interesting.
5．Since farmers rely on the pesticides to reduce the damage of the insect and guarantee the productivity of crops, so that they could keep competitively in the market place.
答案
1．Because of the fierce competition between the students, they how pay much more attention to their final grades than they did in the past.
2．As she searched the Internet, she knew that the advanced functions on the computer were wasting the battery to drain.To overcome this shortcoming, she just needed to shut it off, and then the battery would last for a very long time.
3．From my point of view, people are much happier or more satisfied now with their lives than in the past as society develops.
4．Children spend plenty of time facing the computer screen to surf the internet, playing video games for fun and entertainment, because they think it is very novel and interesting.
5．Farmers rely on pesticides to reduce damage from insects and guarantee the productivity of crops, so that they could remain competitive in the market place.
8）词性问题
部分考生背单词时忽略了词性的记忆，造成动词、名词相互混淆，形容词、副词相互混淆等。
【错误】With the rapid grow of online-shopping，cyberstars have successful attracted a large number of customers.
【正确】With the rapid growth of online-shopping，cyberstars have successfully attracted a large number of customers.
【错误】They innovate and invent more machines to convenient people's life.
【正确】They invent more machines to simplify people's lives.
【错误】Gradually, machines take over people's life and dominant the society.
【正确】Gradually, machines are taking over people's lives and dominating the society.
（2）句子问题
英语句子是结构完整型句子，即基本结构（详见英语五种基本句型）完整，则整个句子结束。但部分考生写句子时，尤其写长句时捉襟见肘，顾此失彼，导致句子成分缺失或叠加使用。
比如主语缺失的问题，在汉语“活到老，学到老”中，没有人会质疑这句话语法有问题，因为这是现代汉语的表达习惯，是约定俗成的用法。而翻译成英语时则不能直译成“Live to the old age and learn to the old age.”，正确的翻译应为：One is never too old to learn.
比主语更容易出问题的是谓语，或者谓语缺失，或者使用双谓语。这个现象也可以从英汉对比的角度来分析，汉语里可以说“他这样做就是支持我们”。这里的“就是”和“支持”都是动词，放在了一个句子中属于双谓语，但是没有错。但是如果翻译成英文“he did this is support us”，则是非常严重的错误。再比如“he is like play football”，这样的错误让人哭笑不得，也是属于思维没有转换过来，不能清楚地掌握非谓语的用法。
1）缺主语
介词短语直接做主语：
【错误】In the case of young adults is not mature enough, I believe that staying with parents will be better.
【解析】in the case of young adults是介词短语，并不能直接做主语。
【正确】In the case of young adults, they are not mature enough; I believe that staying with their parents will be better.
【错误】In this way, it can also cultivate our planning ability when complete a big project which is the essential quality to have in society.
【解析】本句存在when引导的状语从句，从句真正的主语是人，需要把主语加上。
【正确】In this way, it can also cultivate our planning ability when we complete a big project which is the essential quality to have in society.
2）双谓语
【错误】But, if the children is become too dependent on their parents, they will have difficulties in their older lives of becoming independent as the parents will not be available for them anymore.
【解析】is和become连用，双谓语，去掉is。此句还有另外一个知识点需要掌握，请见“主谓一致”部分。
【正确】But, if children become too dependent on their parents, they will have difficulties later on of becoming independent as the parents will not be available for them anymore.
【错误】Personally speaking, I like to choose wait until having a good idea and then accomplish the presentation.
【解析】choose和wait不能这样直接连用，后面的wait应该用非谓语形式。这跟choose不能直接连在like后面而是需要把choose变为动词不定式是一样的道理。
【正确】Personally speaking, I like to choose to wait until I have a good idea, before accomplishing the presentation.
【错误】From what have been discussed above, we may safely draw the conclusion that the final score was determined by many small tests are better for students whatever their final score or the skill mastery.
【解析】如果was determined和are并存，则that引导的同位语从句中仍然是两个谓语，经过进一步分析可知，作者原意是想表达最终分数对于学生会更好。是什么样的最终分数呢?作者想说这些最终分数需要由多个小测试来决定，所以was determined的部分，要么放入定语从句中修饰前面的先行词final score，要么改为determined by过去分词做后置定语。
【正确】From what has been discussed above, we may safely draw the conclusion that the final score determined by many small tests is better for students whatever their final score or the skill mastery.
3）缺谓语
【错误】A good idea means that there has already an exactly direction in the mind, and people can follow the direction step by step until finish the project.
【解析】there be句型中缺少了谓语be动词。而until后面并不是完整的状语从句，这里实际是非谓语做状语，所以finish要改成非谓语形式。
【正确】A good idea means that there has already been an exact direction in the mind, and people can follow the direction step by step until they finish the project.
【错误】When children are doing the things they like out of school, they can meet more people or friends who may not as the same age as them, but they have the same interest.
【解析】在who引导的定语从句中，情态动词may不能单独使用，需要搭配其他动词一起使用，在这里想要表达的是who are not the same age as them，所以应该在may的后面加上be。
【正确】When children are doing the things they like out of school, they can meet more people or friends who may be not the same age as them, but have the same interest.
【错误】The professor argues in the lecture that before the construction, archaeologists should examine whether the old building still value.
【解析】此句中whether引导宾语从句，在从句中the old building是主语，value是名词，可以做表语，这里应该用其形容词形式valuable；同时从句缺失了真正的谓语be动词。
【正确】The professor argues in the lecture that before the construction, archaeologists should examine whether the old building is still valuable.
4）主谓不一致
主谓一致是15分左右考生经常出错的语法点，这同样跟众多考生汉语母语的表达习惯有关。汉语中不会强调“小明到了”中的“到”与“小明未到”中的“到”有何区别。在英语中则会强调这两者时态不一样，所以谓语动词要体现出不同的时态。同样，汉语中不会强调“小明到了”中的“到”和“他们到了”中的“到”有何区别。在英语中则会强调这两者人称的不同，谓语动词应该与其主语保持一致，所以前者用arrives，而后者用arrive原形。笔者总结了三种主谓一致的用法：
语法一致
·单数主语即使后面带有with，along with，together with，like（像），but（除了），except，besides，as well as，no less than，rather than（而不是），including，in addition to引导的短语，谓语动词仍用单数。
·用and连接的并列主语，如果主语是同一个人，同一件事，同一个概念，谓语动词用单数，否则用复数。
·不定式（短语）、动名词（短语）或从句做主语时，谓语动词用单数。
内容一致原则
·通常做复数的集体名词，包括police，people，cattle等，这些集体名词通常用作复数。如：The British police have very limited powers.
·通常做不可数名词的集体名词，包括equipment，furniture，clothing，luggage等。
·可做单数也可做复数的集体名词，包括audience，committee，government，family，enemy，group，party，team，public等。
·the+形容词/过去分词形式”表示一类人或事物，做主语时，谓语动词用复数。
就近原则
·由here，there，where等引导的倒装句中，（有时主语不止一个时）谓语动词与靠近它的主语在数上一致。
·用连词or，either…or，neither…nor，not only…but also等连接的并列主语，谓语动词与靠近它的主语在数上一致。
为了让考生更加清楚地理解，请看下列分析：
【错误】But, if the children is become too dependent on their parents, they will have difficulties in their older lives of becoming independent as the parents will not be available for them anymore.
【解析】is和become连用，双谓语，应去掉is。同时，children是名词复数，所以become应用动词原形。
【正确】But, if the children become too dependent on their parents, they will have difficulties later on of becoming independent as the parents will not be available for them anymore.
【错误】My roommate Ann as well as I are a different teacher for the same subject—math.
【分析】虽然这个句子看似是两个人做主语，但是as well as符合语法一致原则中的第一条：单数主语即使后面带有as well as引导的短语，谓语动词仍用单数。此外，很明显我的室友和我都不是老师，而是有不同的老师，谓语动词应该改为have的正确形式。
【正确】My roommate Ann and I have different teachers for the same subject—math.
5）句中连词的使用
在上一节中，连词与副词的混淆部分，副词在句中做状语，并不影响句子的完整性；连接副词中引导从句的连词则不能单独形成完整的句子，只能称作从句。而连词用来连接两个句子，这时两个句子是并列、因果、转折等关系，不存在主从关系。如果删去连词就变成两个完整的句子。英语中两个并列句子之间必须有连词，否则就要分别点句号。
【错误】Even though the reading material suggests that it is a possible way to rebuild Torreya in its native land where it thrived for thousands of yeas because of the favorable condition in micro-climate for its growth.The professor argues in the lecture that it would not be successful.
【解析】even though引导从句的部分，并不是连词，不能引导独立的一个完整句子。
【正确】Even though the reading material suggests that it is a possible way to rebuild Torreya in its native land where it thrived for thousands of years because of the favorable micro-climate condition for its growth, the professor argues in the lecture that it would not be successful.
【错误】Despite the statement in the reading that there was no other coins to be found at the site.The professor contends that because the Norse did not create permanent settlement at the Native America, so they would pack all the valuable presents like coins with them on the trip and took them back when they returned.
【解析】其一，the statement只是一个名词，后面in the reading that there were no other coins found at the site都是解释说明这个statement是什么，所以缺少了句子主干，标点符号有误。另外，there be句型符合主谓一致中的谓语就近原则，was应该改为were；再者，coin的存在和coin被发现的时间顺序，根据听力内容当时并没有发现任何coin，所以to be found需要改为found。
【正确】Despite the statement in the reading that there were no other coins found at the site, the professor contends that because the Norse did not create permanent settlements in Native America, they would pack all the valuable presents like coins with them on the trip and take it back when they returned.
6）非谓语的逻辑主语问题
很多考生知道状语从句、非谓语做状语等的使用，可以使句式更为灵活。但是部分考生并不清楚地了解非谓语的逻辑主语需要与其句子主干的主语保持一致。
【错误】When solving a problem the best way of finding the solution is just being creative and coming up with many novel ideas.
【解析】when引导的从句部分与句子主干中的主语不一致，不能用when doing。
【正确】When they want to solve a problem, the best way of finding a solution is just being creative and coming up with many novel ideas.
【错误】Moreover, it will increase the quality of the assignment when waiting for a good idea.
【解析】句子主干的主语是it，而when从句中的主语明显不是it，所以不能用非谓语做状语。
【正确】Moreover, it will increase the quality of the assignment if they wait for a good idea.
【错误】When making major purchases, our decisions can be influenced by different sources of information.
【解析】when引导的短语，应该是人们做主语，但是句子的主干的主语却是our decisions。前后主语不一致时，不能使用非谓语做状语。
【正确】When we make a major purchase, our decisions can be influenced by different sources of information.
（3）英语五种基本句型
1）主谓句
这种句子是指句子主干为主语和不及物动词做谓语的句子。
例1 I came! I saw! I conquered!
He quits.
The quality of products in their company has been suffering.
2）主系表句
句子主干中谓语动词为系动词的句子为主系表结构的简单句。
常见的系动词有：be, turn, grow, get, remain, stay, keep，以及与感觉有关的动词 look, sound, smell, taste, feel等。
例1 Most children seem to be better at remembering bad habits than developing good ones.
Albert Einstein was a famous professor of physics.
My dream is to study abroad.
3）主谓宾句
这种句子是指句子主干为主语、及物动词做谓语和宾语的句子。
例1 We should not ignore the impact of watching TV on intellectual stimulation.
Over-irrigation will pose a threat to crop yields.
Video games have a chronic influence on their academic performance.
4）主谓双宾句
句子主干为主语、谓语（及物动词）、间接宾语和直接宾语，这类句子中的及物动词常为：bring, fetch, give, hand, leave, lend, offer, owe, pass, pay, book, buy, call, choose, cook, do, fetch, find, get, keep, leave, save, win等。
例1 Discoveries concerning a therapy against malaria won Tu Youyou, a herbal expert, the Nobel Prize in 2015.
Give a man a fish and you feed him for a day.Teach him how to fish and you feed him for a lifetime.
He promised his mother a better score after he is given the extra pocket money as a prize and reward.
5）主谓宾宾补句
这类句子，主干部分包括：主语、谓语（及物动词）、宾语和宾语补足语。
例 The technology of genetic modification allows people to have healthy food.
Having regular meals with relatives helps people maintain a harmonious family.
Doing excessive exercise may put people at risk of injury, especially for the elderly.
（4）汉译英：句子结构分析及翻译练习
·一些人不支持过度使用社交媒体。
Some people disapprove of excessively using social media.
解析：主语some people，谓语不及物动词disapprove。主谓结构。
·我们不应该拒绝给孩子做自己喜欢之事的机会。
We ought not to deny children the opportunity to do whatever they like.
解析：主语we，谓语ought not to deny，间接宾语children，直接宾语the opportunity。主谓宾间宾直宾结构。
·能够清楚表达的老师很容易被理解。
Teachers who express themselves clearly make themselves mare easily understood.
解析：主语teachers，谓语及物动词make，宾语themselves，宾语补足语understood easily。主谓宾宾补结构。
·他们也许不能安排好时间。
They may fail to create a good timetable.
解析：主语they，谓语不及物动词fail。主谓结构。
·大学生做兼职有助于减轻父母负担。
For university students, doing a part-time job is beneficial to reducing parents' burden.
解析：主语doing part-time jobs，谓语系动词is，形容词beneficial做表语。主系表结构。
·工作很忙的人通常吃饭不规律。
People with a heavy workloads usually have irregular meals.
解析：主语people，谓语have，宾语irregular meals。主谓宾结构。
·当国家只关注经济发展时，环境和生态问题就不断出现。
Environmental and ecological problems have surfaced when countries only attach importance to economic development.
解析：主语environmental and ecological problems，谓语have surfaced。主谓结构。
·对我而言，如何与人良好沟通仍然是个谜。
How to communicate well with others remains a puzzle to me.
解析：主语how to communicate well with others，谓语系动词remains，表语a puzzle。主系表结构。
·滥砍滥伐导致栖息地的破坏。
Excessive deforestation destructs habitats.
解析：主语excessive deforestation，谓语destructs，宾语habitats。主谓宾结构。
·男生尖锐的言论令老师无言以对。
The boy's sharp remark left the teacher speechless.
解析：主语the boy's是remark，谓语是及物动词left，宾语是the teacher，宾语补足语是speechless。主谓宾宾补结构。
·近期，有些学生表现出对老师的不尊敬，这在群众中引起了激烈的争议。
Recently, some students have shown their teachers less respect, which arouses a heated debate among citizens.
解析：主语some students，谓语及物动词show，间接宾语their teachers，直接宾语respect。主谓间宾直宾结构。
·这种趋势在过去几十年已经开始。
This trend has begun in the last several decades.
解析：主语是this trend，谓语has begun。主谓结构。