although和however的用法.ppt

1、Unit 7- Unit 12 重点,therefore, although和however的用法 现在完成进行时 虚拟条件句 进行时的被动语态 间接引语 我们先来看看therefore, although, 和however的用法。 therefore表结果,比so显得更正式一些，在句中常与and连用； 如：He worked day and night, and therefore he was able to buy a new sports car. although表示“虽然，但是”所引导的从句可以放在主句前面，也可以放在主句的后面。在主句前面时，要用逗号与主句隔开；,如: Alth

2、ough they were 75 years old, they still played tennis every day. ； 由于although的中文意思是“虽然，但是”，很多学员容易犯的一个错误是用了although后，又用but，这在英语里是错误的。 however表示转折，与but意思相同，但是较正式的说法。However在句中位置较灵活，在句首时，后面常用逗号。 如：He was wealthy. However, he was very mean(吝啬的).,现在完成进行时。现在完成进行时强调动作从过去某个时间一直持续到现在，而且还要继续下去。其基本构成是：have / h

3、as + been doing （基本结构） have / has not + been doing （否定形式） Have / has + 主语 + been doing （一般疑问句形式） 特殊疑问句形式将疑问词置于句首我们来看一个例子： Ive been working here for three years.,I havent been working here for three years. Have you been working here for three years? How many years have you been working here? Who have

4、 been working here for three years?,这几个单元中的一个难点是虚拟条件句。 虚拟条件句表示与事实相反的愿望、假想。同学们先掌握与现在事实相反的虚拟条件句。其结构是： If + 从句主语 + 动词过去式，主句主语+ would (d) +动词原形。 例如： If I had the time, Id make something better. 在这种与现在事实相反的虚拟条件句中，需要注意的是，不论主语是什么人称，be动词都常用were， 如： If I were you, Id ask her.,现在我们看看进行时的被动态形式。进行时被动语态分为现在进行时被动

5、语态和过去进行时被动语态。这两种被动语态的时态是通过be动词来体现的。我们分别来看它们的基本结构： 现在进行时被动语态： be ( am / is / are) + being + 动词过去分词 过去进行时被动语态： be (was / were ) + being + 动词过去分词 这两种被动语态的否定形式和疑问句形式都是在be动词上发生变化。例如： His behaviour is not being blamed by the public. Were 200 people being treated? Where were 200 people being treated?,间接引语也学习过。要注意的是间接引语中主句时态和从句时态的一致性原则。一般来说，如果主句谓语动词为过去时，在将直接引语变为间接引语时，要将直接引语中的谓语动词时态往前推一个时间档，即一般现在时变为一般过去时，一般过去时则变为过去完成时，看下面的例子： “ My parents live in Beijing,” She said. She said her parents lived