柠檬脾气个人GMAT语法笔记,综合Manhattan SC及 prep语法笔记
have + 动词过去分词
其他形式： But for N, S + should/would/cold/might + V / (have Vpp.) 若不是N, S应该 .
= If it were not / (had not been) for N, S
= Were it not for N / (Had it not been for N), S
= Without N（介词只有without可表虚拟语气）, S （为什么感觉时态怪怪的）
二、命令虚拟 v. that + do (should一定要省略)
1.命令性动词（只能用that从句的命令虚拟语气，不能用不定式）：require， demand, dictate, insist, mandate, propose, recommend, request, stipulate（规定）, suggest
（*其中propose,当句子中的两个动词发起者均是一个主语时，可以用不定式。
The attorneys proposed to meet the following day.）
2.只能用不定式的动词，这些动词后面不能加宾语从句 只能用 v. sb to do sth allow, forbid, persuade, want (allow that…承认)，force, permit, prohibit
3.既可以接that从句的命令虚拟语气，又可以接不定式：ask, beg, intend, order, prefer,
urge, require
4.具有命令性的词汇的名词形式同样应用虚拟语气
Right: His demand THAT he BE paid full severance was not met.
5.形容词性的命令词汇既可用虚拟语气，也可用不定式
it is + adj.+that..be../ It is +adj.+to do
adj.: advisable, crucial, desirable, fitting, imperative, important, essential, mandatory,
necessary, preferable, urgent, and vital.
四、if…then 结构 then通常省略
(1)表示确定
IF Present, THEN Present.
IF Sophie EATS pizza, THEN she BECOMES ill.
This pattern is equivalent to whenever: WHENEVER Sophie EATS pizza, she BECOMES ill,
(2) 表示某种程度上的不确定
IF Present, THEN Can or May.
IF Sophie EATS pizza, THEN she MAY BECOME ill. (3) 确定-用于将来时态（现在发生的某些事情造成将来的影响）：
IF Present, THEN Future.
IF Sophie EATS pizza tomorrow, THEN she WILL BECOME ill. Another possibility for the Particular Case (in the present) is Present Perfect: I f Sophie HAS EATEN pizza, then she WILL BECOME ill.
(4) 不确定-将来时态：（对现在、将来的虚拟）
IF Hypothetical Subjunctive（虚拟语气）, THEN Conditional（情态动词）.
