用there is句型说明有必要的

用there is句型说明有必要的
用there is句型说明有必要的

用there is句型说明有必要的
常见结构：“There + be + 主语 + 地点状语（或时间状语）”.存在句的“there”要弱读.存在句的句型转换：
一. 肯定陈述句
例：There is a dictionary on the desk.（桌子上有一本字典.）
二. 否定陈述句
例：There isn’t a dictionary on the desk.（桌子上没有字典.）
三. 一般疑问句
例：Is there a dictionary on the desk?（桌子上有一本字典吗?）
there be与have的比较
 ■不同之处
一、用法不同
there be 表示某个时间或地方“存在”某人或某物,而have表示主语“拥有”某人或某物,作宾语的某人或某物属主语所有.
二、结构不同
there be + sb./sth. +时间/地点(副词或介词短语)；sb./sth. + have +sb./sth. else
There are some children in the garden.花园里有几个孩子.
She has three cars. 她拥有三辆汽车.(汽车是属于她的)
 ■相同之处
 表示某物体在结构上“装有”“配备有”“固有”时,两者均可用.如：A clock has a round face.= There is a round face on a clock. 钟面上有一个圆型的钟盘.
Each house on the street has a small yard.= There is a small yard in each house on the street. 这条街旁的每栋房子都有一座小花园.
2. 当have表示“包括”时,可以用 There be 替换.如：
A week has seven days. =There are seven days in a week. 一周有七天.
3. 当 have 表示“存在”时,可以用 There be 替换,如：
Our village has only one street.=There is only one street in our village. 我们村里只有一条街.
 
存在句型
1.结构:There + be + 实际主语 +其它成分
 e.g.There is a similar system in their country.
   There are two other points to consider.
 
2.注：(1).there be 句型中易出现两个谓语的错误
  (2).there be 句型中的主谓一致是遵循就近原则
3.be动词的变化
    1)． be 动词时态有一般现在时,一般过去时,一般将来时,现在完成时.
     e.g.  There is not enough land by the sea.
 There are also instructions for making wine.
 
     e.g.  There was only one entrance to the hotel when I came last year.
           There were a lot of demonstrations in Americalast month.
e.g.As a result,there will be many new jobs for workers.
 e.g.There have been great advances in telephone equipment in the last quarter of the twentieth century.
 
2）存在句在be部分可以使用情态动词+be
  e.g.There may be two possible answers.
     Nowhere else in the world can there be such a quiet,beautiful place.
3).半助动词＋be   (seem,appear,happen)
    There seem/ happen/ appear to be
  There appears to be a mistake.
 There seems to be something wrong with it.
 
4) 除be外,某些表示存在概念的不及物动词如：exist,remain,happen,occur,come,lie,stand,live等,也能用于存在句.
     There stands a huge building behind the tree.
1．桌上有一只笔和一些书.
There is a pen and some books on the desk.
2.今天的报纸上有很多新闻.
There is a lot of good news in today’s newspaper.
 
3．地上有一双鞋,这鞋是我的.
There is a pair of shoes on the floor.The shoes are mine.
4.二楼住着一个年轻人,他是一个艺术家.
   On the second floor,there lived a young man,who was an artist.
5.在美国有五个不同的时区.
There are five different time areas in theUnited States.
6.有些节目介绍英国的生活.
  There are some programs which introduce the British life.
  There are some programs introducing the life inBritain.
9.你知道如果出了事故该怎么办吗?
 Do you know what to do/we should do if there is an accident?
 
10.当你开始工作时,有许多事情要学习
There are many things to be learnt/that you should learn when you start working.

there is necessary to...