from, to, with, before, for ... 这些都是介词
prepositions generally come before nouns,
pronouns and gerunds.
介词通常用在名词、代词、动名词（ing）之前，一般构成介词短语， 介词+动词原型构成动词不定式，不是介词短语。
I encourage you `to study`.
* 比如这里的 `to study` 就不是介词短语，而是动词不定式
介词不能单独存在
介词 + 名词 = 形容词 / 副词
This is a book.
This is a good book.
This is a book about car.
当我要描述这是一本好书的时候，只需要一个形容词good就可以完成；
但是当我描述这是一本关于汽车的书，此时，找不到一个形容词可以直接表达 关于汽车的 这个概念，所以这里就需要人为创造了， 用 介词 + 名词 构成一个整体，相当于一个形容词，这样就完成了句意的表达。
副词也是同样的道理：
I stand here.
I stand under the tree.
当我想表达 站在树下 的时候，没办法找到一个副词可以直接表达，所以这里通过用 介词 + 名词 构成一个整体，相当于一个副词。
Preposition + Object （介词 + 宾语）
// 1. preposition + noun （名词）
Please listen to the story.
Please listen to this true story.
Please listen to what I must say.
A preposition can come before a noun，a noun phrase or a noun clause.
介词可以放在名词、名词短语或名词从句的前面。
A preposition can also come before more than one kind of pronoun.
介词也可以出现在多种代词的前面。
// 2. preposition + pronoun （代词）
look at me
look at yourself
look at that
And finally a preposition can be followed by a gerund or a gerund phrase.
最后，介词后面可以跟着动名词或动名词短语。
// 3. preposition + gerund 动名词（ing）
he joked about dancing. // 他开玩笑说跳舞
he joked about dancing in a contest. // 他开玩笑说在比赛中跳舞
介词的作用
Prepositions and their objects form prepositional phrases.
We need prepositions to give information about time,location, direction, reasons.
There are different ideas and different relationships that prepositions help us express.
Generally speaking, we`ll find prepositions toward the end of a sentence.
We can start a sentence with a prepositional phrase.
介词及其宾语构成介词短语。
我们需要介词来提供关于时间、地点、方向和原因的信息。
介词有助于表达的不同想法和不同关系。
一般说来，去一个句子的末尾找介词。
我们也可以以介词短语开始句子。
`In the morning`, I drink orange juice
But often we find the prepositional phrases toward the end , after the verb.
但我们常常在动词后面找到介词短语。
for example
I worry `about you`
I'm happy ` for you`
Some sentences may have two objects. In that case， you likely have a direct object
and an indirect object.
A direct object is the object of a verb.
The indirect object is the object of a preposition.
direct object = object of a verb
indirect object = object of a preposition
有些句子可能有两个宾语。在这种情况下，你可能有直接宾语和间接宾语
直接宾语是动词的宾语
间接宾语是介词的宾语
here's an example:
what am I doing right now ?
我现在在做什么？
I'm giving an `explanation` about `grammar`
我在讲解语法
* explanation 和 grammar 两个宾语
What am I giving ？
我在给什么？
An explanation
一个解释
give + explanation
verb + direct object
* give是动词，explanation 是直接宾语
About what ？
关于什么？
About grammar.
关于语法
* about 是介词，grammar 是间接宾语
what if I say：
I'm giving you an explanation about grammar。
我在给你讲解语法
You ... Explanation ... Grammar
In this case, what I'm really saying is...
在这种情况下，我真正要说的是...
I'm giving an explanation about grammar `to you`.
With this structure :
具有这样的结构：
give (something) to (someone)
I'm allowed to separate the preposition and its object and move that pronoun you to an earlier position.
我把介词和宾语分开，把代词 "you" 移到更早的位置。
I'm giving you an explanation about grammar
Using Prepositions (使用介词)
For now ，just know that in most cases a preposition is directly followed by its object.
But as you saw，there are times when we can separate or need to separate.
就目前而言，只要知道在大多数情况下介词后面直接跟着宾语就可以了。
但是正如你所见，有时候我们可以将介词和宾语分开，或者需要将介词和宾语分开.
The object from its preposition.
This happens with the preposition TO.
将宾语与其介词分开
这与介词TO一起发生
For clarity or for emphasis，
We leave the preposition and object together
为了清楚或强调，我们把介词和宾语放在一起
image.png
But if I don't need to stress who or what is doing the receiving， I can move the object to an earlier position. After the verb and before the direct object.
但是，如果我不需要强调接收者是谁或接收者正做什么，我可以把宾语移到更早的位置。在动词之后和直接宾语之前。
image.png
We also see separation of a preposition and its object in questions.
我们还看到介词与其宾语在疑问句中的分离
image.png
- what, who 都是间接宾语；about、for 是介词
Word Order & Sentence Structure
while we're talking about word order and sentence structure，let me ask you a question.
image.png
In this sentence，how many objects do you see？
hopefully， you see two.
你看到几个宾语？希望你看到两个
image.png
Is one of them a direct object ？
其中之一是直接的对象吗？
No.
"lobby" and "noon" are objects of prepositions.
we have two prepositional phrases.
不是."lobby" 和 "noon" 是介词的宾语. 我们有两个介词短语 in, at .
image.png
When we have a prepositional phrase of place and a prepositional phrase of time, place usually goes before time.
当我们有"地点"的介词短语和"时间"的介词短语时, 地点通常是在时间之前。
Quiz
image.png
Here, out is not a preposition
Your first clue is that there is no object.
Out here is a particle.
The verb look and the particle out form a phrasal verb.
This phrasal verb means be careful.
It serves as a warning.
image.png
out不是介词，你的第一个线索是没有宾语, out在这里是一个小品词，动词look和小品词out构成一个短语动词，这个短语动词的意思是小心，作为警告
image.png
To study is an infinitive.
TO plus the base form of a verb is the infinitive.
A verb form not a prepositional phrase.
to study 是不定式， TO + 动词原型 是动词不定式，不是介词短语
网友评论