主谓一致
一. 原则
1.主谓必须同时存在
连词开头的句子一定要有主句，否则是错误的
becase, if, when, although从句开头的句子，若从句后面没有逗号，一定错。
2.主语和谓语从逻辑上一定要合理，且主语和谓语在单复数上要一致。当不清楚主语是否应该是单数/复数的时候，看宾语，想造成这个宾语的主语是什么样的★
e.g. The discovery of new medicines (was/were) vital to the company's growth.
若不知道主语是否单复，就想是什么造成公司的上涨。肯定是一件事。所以是单数 3.找到真正的主语---去掉介宾短语，从句及动词短语修饰词
介宾短语（of,／for by,／in,／with／,at,／to,／on,／from 后面的词不是主语可以忽略，所以要学会看到介词跳读。）
从句始终只是句子中辅助的成分，类似大形容词，大名词或大副词
e.g. Pong is a classic game from which HAVE descended many current computer pastimes. (Pong is a classic game from which many current computer pastimes HAVE descended.) 4.不能确定的话，一般用单数谓语动词 规律
1.and 连接几个不同的（单数）名词的时候构成复数结构，谓语动词要用复数
2.就前原则的短语
with; along with; together with; in addition to; as well as; accompanied by; including; more than; no less than; besides; except;
3.就近原则：or, nor, either…or; neither…nor； not...but.. (not that…but rather that…); not only…but also;
（注意，只有either，neither做主语时，谓语动词用单数）
5.模糊代词，谓语动词用单数：(-one, -thing)
Anyone, anybody, anything, No one, nobody, nothing, not one Each, every (as pronouns) Someone, somebody, something Everyone, everybody, everything, whatever, whoever Either, neither (may require a plural verb if paired with or/nor)
6.以下代词的单复数由后面的名词决定： Some of, Any of, None, All of, More/Most of, no
half of, majority, minority, plurality of, the rest of, 分数/百分数 If you want to indicate the totality itself, then use a singular verb form. e.g. The majority of the students in this class ARE hard workers. In the Senate, the majority HAS coalesced into a unified voting block.
7.each/every做主语，单数：
由each/every开头+任何名词（不论单复数）单数谓语 Every dog and cat HAS paws. 复数名词（代词）+ each + 复数谓语 They each ARE great tennis players
9. a group of/ a body of/ an array of/ a series of/ s asset of/ a portion of+复数名词，谓语动词用单数！
10. a total of, an average of+ 复数名词， 复数v the average of + 复数名词， 单数v
10.一些表示学科的词（physics, mathematics）、一些活动－有氧运动（aerobics）和一些疾病－糖尿病（diabetes）虽然以S结尾，仍属于单数名词，谓语动词用单数 当statistics做“统计数据”，economics做“经济政策”时，复数v； news 谓语动词用单数 species 物种（单数）
4.集合名词看做整体，谓语动词用单数：
People: agency, army, audience, class, committee, crowd, orchestra, team Items: baggage, citrus, equipment, fleet（舰队，小河）, fruit, furniture 如果说一种动物比如 cat（无冠词）。。。后面代词用they
11. 定冠词the+姓氏、朝代、部族名称等，表示一群人，是集合名词，谓语要求用复数。如the Smith 为史密斯一家，the Shang表示商朝人等。
12. only作形容词，表示唯一的一个，既然是唯一的一个，后面修饰的名词就不能是复数，否则语义及单复数前后矛盾 （only后面不能加复数名词？）
13.单复同形的词：fish，species （单复同形的名词单独出现看做复数）
14. (not) one of the+名词复数+单数形式谓语；Not one of =none of
not one of 全部用单数 Not one of my friends IS here this weekend (none of may friends are?) 但是none of 做主语 由后面的名词决定
16. one of + 复数名词+ that从句， that从句修饰复数名词，从句动词用复数 the only one of + 复数名词+ that从句， that从句动词用复数
17. medium单数-media复数； phenomenon单数- phenomena复数 18. the first trenches 做主语，用复数
8.从句做主语，单数
1). what引导的名词性从句中从句谓语动词的单复数情况：
what后面“什么时候用单数,什么时候用复数”根据动词后面的名词的单复数来定.
2).what (who/why/how/whether) 引导的名词性从句做主语时,主句谓语动词用单数一定是正确的：
********有时也参照下面的单复数规则：
(1)What在从句中做主语，主句谓语由what从句的谓语决定。
1) What is difficult to understand is A.；What are difficult to understand are A and B.
(2)what在从句中做宾语，主句谓语由主句表语/宾语决定what they want are XX,XX&XX。 2) What his father left him are a few English books.
平行结构
一. 原则：结构相似，词性相同，形式对称，概念对等，功能相同，意思单一 （主被动语态需要相同么？） 二. 平行标志词：
连词：And, or, but, yet （but只能连接两个并列成分）
短语：both ?and, either or; neither nor, not but, not only.. but also (not only…also… not
onl..but…), rather than, from..to..; between..and..; as well as (not…but… > rather
than > instead of) 一般出现instead of 错
三. 重要考点：
1.动名词可以和普通名词平行，但加宾语的动名词不行
实体名词（时间，地点，人，事件）和动作名词（指示一种动作）不能平行 简单动名词不能和复杂动名词平行。且只有复杂动名词才能与动作名词平行 简单动名词 本质还是动词，可以有动词功能
e.g. Tracking satellites accurately is important for the space agency. 复杂动名词“Nouns Through and Through.”
e.g. The accurate tracking of satellites is important for the space agency. （彻头彻尾的名词，一般有冠词修饰，且为of结构或者名词+动名词结构 the wine tasting） 现在分词可以和过去分词并列 副词可以和介词短语并列
名词短语可以和what从句平列 2.从句并列时，时态可不一致。
不同类型的从句不能并列; 不同功能的定从不能并列
ex. n. who….and n. whose… 对； n. where…and n. who… 错误
3.平行概念对等：抽象名词和具象名词，整体概念和局部概念，泛指和特指均不对等，不可并列
4. there be句型的平行要补出there be. (不要随意排除there be)
ex. There are no legal limits, as there are for cod and haddock, on the size of monkfish that can be caught, a circumstance that contributes to their depletion through overfishing.
四。平行结构的省略
1.不定式，情态动词，助动词可以省
to do A, and (to) do B… 当比较多于两项时，后面的与第二项保持一致 2. 从句开头的“引导词不可以省略，即使引导词一样”；（从句！曼哈顿原话：两个从句平行的话为了避开歧意必须都要用引导词引导）
I want to retire to a place WHERE I can relax AND WHERE I pav low taxes.
但是“引导词”前面的词不可以省略！(即平行成分不可或缺，检验办法：去掉没有问题的平行成分链接到谓语来检查是否ambiguity)
Wrong: Ralph likes BOTH THOSE WHO are popular AND WHO are not.
Right: Ralph likes BOTH THOSE WHO are popular AND THOSE WHO are not. 3. 介词短语并列，介词尽量保留
Wrong：The experiences we have childhood influence our behavior in adulthood. Right: The experiences we have in childhood influence our behavior in adulthood.
The bird itself is vanishing in the northeastern United States as a result of residential and industrial development and of changes in farming practice
五。隐含的平行：
To Be形：Known to be, be thought to be, eastimate X to be Y
XY形：Consider XY, Declare XY, Make XY, （make 与 consider 用法一致） As形：X Act as Y, the same as Y, as X, so Y,？？
Think of X as Y, View X as Y, Regard X as Y For形：Mistake X for Y
To形：Compared to X, Y, in contrast to X, Y
★系动词两边的成分要并列：表达的是“主语是什么／主语在什么情况下 be, appear, become, feel, grow, look, remain, represent, resemble, seem, smell, sound, taste, turn, stay
系动词表示的是两边的东西必须是同质的，词性相同 Wrong: The bouquet of flowers WAS a giving of love. Right: The bouquet of flowers WAS a gift of love. 词义也要相同
Wrong: Upon being nominated, this politician REPRESENTS a step forward in urban-rural relations in this country.
Right: The nomination of this politician REPRESENTS a step forward in urban rural relations in this country.
Just as??as的用法
“正如A?，B也?，”“B就像A一样” (A,B以同样的方式)
“随着?.,?.也?”第一个分句用as，第二个用so引导。发生在第二个分句的情况在一定程度上取决于发生在第一个分句的情况，而且两种情况同时发生。 As the cost of keeping money in the bank increases, so it’s spend faster. Just as A do, B do； A do, just as B do. A，B平行对等
Just as ? , so/as ? (Just) as you practice, so shall you play.主从句要尽量形式对称 Just as ? , so too ? 主句要部分倒装(so too后是主句) Just as you sow, so too will you reap
Just as you practice piano regularly, you should study regularly. **前后都要用句子，不能只用短语。
so with是错误结构。(prep 1-15)
as with的结构在日常语法中是对的(意思为“正如??的情况一样”， 看作是as is the same with的省略式，with 后面常跟名词、动名词或what从句)：
(1) As with other forward contracts, the cash settlement amount is the amount necessary to compensate the party who would be disadvantaged by the actual change in market rates as of the settlement date.
(2) As with most diseases and disasters, the young suffer the most. 就像大部分的疾病和灾难一样，最遭罪的是年轻人。
(3) As with drawing a picture, you should be patient and careful in doing this job. 正如画画一样，你应该耐心并且认真做这项工作。 但用于GMAT语法中，需要有其他结构与之平行:
大全938. With diamonds, as with all gems, you should ask for a written description of your purchase; the description may prove useful later if you have reason to believe the jeweler misled you.
单纯的as with the case + prep. (of/with/in) + sth.结构错误，应该用as is the case + prep. (of/with/in) + sth.
prep 1-39 As is the case with traditional pharmacies, prescriptions are the cornerstone of a successful on-line drugstore, since it is primarily prescriptions that attract the customers, who then also buy other health related items.
in the same way that…, as/so…也是错误结构
like…, so/as…也是错误结构：like的比较必须是严格对称的