副词和介词是什么?分别在什么情况下使用?

副词和介词是什么?分别在什么情况下使用?
最好说明清楚,并且举例子!
应该如何改写副词呢?
请大家补充一下在什么情况下使用副词。

1.副词是一种用来修饰动词,形容词,副词或全句的词,说明时间,地点,程度,方式等概念.
副词在句中可作状语,表语,短语.
He works hard.
他工作努力.
You speak English quite well.
你英语讲的很好.
Is she in
她在家吗?
Let's be out.
让我们出去吧.
Food here is hard to get.
这儿很难弄到食物.
1) 多数副词都可以放在动词的后面,如果动词带有宾语,副词就放在宾语后面.
I get up early in the morning everyday.
我每天早早起床.
He gave me a gift yesterday.
他昨天给了我一件礼物.
She didn't drink water enough.
她没喝够水.
The train goes fast.
火车跑得快.
We can go to this school freely.
我们可以免费到这家学校学习.
They left a life hardly then.
当时他们的生活很艰难.
He has a new hat on today.
他今天戴了一顶新帽子.
I have seen this film twice with my friends.
这部电影我和朋友看过两次.
2) 副词修饰形容词,副词时,副词在前面,而被修饰的词在后面.
It's rather easy,I can do it.
这很容易,我能做到.
He did it quite well.
他做得相当好.
It's rather difficult to tell who is right.
很难说谁是对的.
It's so important that I must tell my friends.
这件事太重要了,我得告诉我的朋友.
It's much better.
好多了.
3) 频度副词可放在实义动词的前面,情态动词和助动词的后面.
I often help him these days.
这些日子我经常帮助他.
I always remember the day when I first came
to this school.
我常常记得我第一次来学校的那一天.
You mustn't always help me.
你不能老是帮助我.
He seldom comes to see us.
他很少来看我们.
We usually go shopping once a week.
我们通常一周买一次东西.
The new students don't always go to dance.
新学生并不时常去跳舞.
4) 疑问副词,连接副词,关系副词以及修饰整个句子的副词,通常放在句子或从句的前面.
When do you study everyday?
你每天什么时间学习?
Can you tell me how you did it?
你能告诉我你如何做的吗?
First,let me ask you some questions.
先让我来问几个问题.
How much does this bike cost?
这辆车子多少钱?
Either you go or he comes.
不是你去就是他来.
The students were reading when the teacher came into the classroom.
当老师进教室时,学生们正在读书.
5) 时间副词和地点副词在一个句中,地点副词在前面时间副词在后面.
We went shopping in the supermarket at 9 o'clock yesterday.
昨天九点钟我们到超市买东西了.
What were you doing in the classroom yesterday afternoon?
昨天下午你在教室里干什么?
The accident took place in the Eleven Avenue one hour ago.
一小时前十一号大街发生了一场事故.
2.介词是一种用来表示词与词,词与句之间的关系的词.在句中不能单独作句字成分.介词后面一般有名词代词或相当于名词的其他词类,短语或从句作它的宾语.介词和它的宾语构成介词词组,在句中作状语,表语,补语或介词宾语.
The car hit against the tree.
汽车撞了树.
have bought a book about Shakespearean.
我买He went home after school.
他放学后就回家了了一本有关莎士比亚的书.