第一篇英语语法

1、Grammar 1 ——as if 虚拟语气的用法。as if ：The subjunctive subjunctive tone is when the speaker thinks that the sentence is untrue or very few may happen or exist.（从句用虚拟语气的情况是当说话人认为句子所述的是不真实的或极少数有可能发生或者存在的情况。）

2、First, if the clause indicates the opposite of the present fact, the predicate verb is used in the past tense.（第一，如果从句表示与现在事实相反，谓语动词用一般过去时。）

3、Second, if the clause indicates the opposite of past facts, the predicate verb uses "had + past participle".（第二，如果从句表示与过去事实相反，谓语动词用“had+过去分词”。）

4、Third, the clause indicates that it i衡痕贤伎s contrary to the facts in the 熠硒勘唏future, and the predicate verb uses "would / could / might + verb original form".（第三，从句表示与将来事实相反，谓语动词用“would/could/might+动词原形”。）

5、If the content expressed by the clause is a fact or may be a fact, a declarative tone can also be used.（从句表示的内容若为事实或可能为事实，也可用陈述语气。）

6、Garmmar 2——it is ... that ... 强调句。When it is necessary to emphasize t茑霁酌绡he subject, object, adverbial in the sentence, we often use "it is (was) + emphasized part + that (who)".（当需要强调句中主语、宾语、状语时，我们常用“it is(was) + 被强调部分 + that(who)"。）

7、First, emphasize subject, object, adverbial of place and adverbial of time.（第一,强调主语、宾语、地点状语和时间状语。）e.g. : It was three books that he read in the library yesterday .

8、Second, when the emphasized part refers to people, you can use that and who; when referring to things, only use that.(第二，当被强调部分指人时，可用that，也可用who；指物时，只用that。)

9、Third, only use that to emphasize adverbials, not when, where.（第三，强调状语时只用that，不用when，where。）e.g.:It is at 5 o'clock that the train will arrive .

10、Fourth, the emphasized 衡痕贤伎sentence of general interrogative sentences is "is (was) it + that: special interrogative words + is (was) + that".（第四，一般疑问句的强调句为“is(was) it + that :特殊疑问词 + is (was) + that "。）e.g.:When is it that you will set off ?