Verb form，语气，语态
1，
(1)介词后面就是跟名词或者名词性质的东西，而不是有主谓结构的完整事情，如果想表达一个事情就改用从句。
例：
Wrong：the thesis of consumer having....变成了特定的consumer的一种thesis
Right：the thesis that consumer have.....描述thesis的内容，一件事情。Consumer也是泛指
Wrong：we are hoping for x 表达不出具体时态
Right: we are hoping for a recovery. 因为we just hope for a recovery
(2)there be结构的区分(prep 08—237)
Concerns about public health led to the construction between 1876 and 1904 of three separate sewer systems to serve metropolitan Boston.
A. Concerns about public health led to the construction between 1876 and 1904 of three separate sewer systems to serve
B. There were concerns about public health leading to the construction between 1876 and 1904 of three separate sewer systems serving (A)
区分：most importantly, it doesn't emphasize the right thing: the main skeleton of the sentence is "there were concerns", which is NOT the main point. in choice (a), the main skeleton is "concerns led to the construction", which IS the main point.也就是说there be结构还是强调一个名词的结构，加上修饰语就变成了某一类特定的事物
"to serve" is better than "serving", because
* "to serve" implies a sense of purpose or intention (which is precisely what is to be conveyed here), and
* "serving" implies that the systems were already serving boston at the time when they were being constructed.
2，
(1)Rather本身做副词是要和would rather/had rather，或者放在句首(Rather,....)使用，否则单独以副词身份出现都是“十分”(quite/to a certain degree)的意思。insead做副词。
(2)不合理结构：able to be done, capable of being done, unable to be done!错误!(有能力被做)
complex gerund的识别方法：(a/an/the)+(adj)+Ving+ of + O; O Ving
例：the running of marathons;marathons running
(3)Can和be able to的区别：can只有两种形式：can和could。 Be able to就可以使用将来时，有多种时态。所以就是从时态和对称的角度来看哪个角度合适。
3，
关于being和having结构：
(1)being在以下情况必错：1>n+being done;2>n+being n/adj;3>there being
(2)you should NEVER start a modifier with "being". in any such modifier, you should always be able to eliminate "being".(以及表达IDENTITY or CHARACTERISTICS时是错误的)
例如：Being a avid gamer, Jim plays everyday - Incorrect
A avid gamer, Jim plays everyday - Correct
Being very reluctant to do X, Jim...----Incorrect
Very reluctant to do X, Jim...-Correct
另注意和其余选项比较，选最优的：
The one time when "being" is grammatically necessary is when having a property is the idea you are trying to describe:
例如：Being tall is helpful for basketball players.
这也是极特殊两种being可以视为语法正确的结构：1>动名词; 2>进行时的被动语态(eg. Sth is being done)
(3)Having必错：1>n+having done;2>n+having been done，即不可用做限定性修饰
(4)Having done 和 having been done都不是动名词，因此不能充当名词成分。
(5)Having done可以做非限定性修饰，短语中表达的内容发生在主句动作之前。
(6)When having done 结构一定错，因为不应该有 when。单是 Having done 就够了。原因是 having done 是过去，而 when 是当时，所以有冲突。同样的after having done也是错误的结构(同理的after/before A do sth. when B do sth.或者after/before when，这样的结构都是不好的。)
4，
as with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。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.
l in the same way that…, as/so…也是错误结构
l like…, so/as…也是错误结构：like的比较必须是严格对称的。just like都是很wordy的
5，to和in order to的比较：(prep1-13 1-65 1-144)
(1) in order for sth. to do/be，in order that和in order to do sth.都可以。
I am saving money in order that I can buy a house. 我正在攒钱，以便我能买一所房子。
(2) in order to 只能做状语;不定式可以做主语，因为它可以做名词成分。
(3) in order to因为只做状语，所以不会修饰前面名词，to do可以做定语，所以有修饰前面名词的功能。
(4)不定式的用法：当不定式修饰其逻辑宾语时，如Can you give me some work to do? 不定式的后面是不能带宾语的。
6，
虚拟语气：
虚拟条件句的四种形式：
But for N, S + would + V / (have Vpp.) 若不是N, S应该….
= If it were not / (had not been) for N
= Were it not for N / (Had it not been for N)
= Without N(介词只有without可表虚拟语气)
7，
被动语态的使用往往是不强调动作的发出者，这个需要特别注意!例子：
The chief executive’s plans were announced on Wednesday------OG解释：the passive verb form were announced suggests that someone other than the chief executive is outlining the strategy. We should make it clear that the chief executive is doing the announcing!
If条件句的格式问题：(摘自OG)
In a conditional sentence if X, (then) Y, If one clause is passive, the other should be passive; if one clause is active, the other should be active, too.