英语人教版八年级下册Unit8 SectionA Grammar Focus.ppt

1、Unit 8,Unit 8 Have you read Treasure Island yet?,Section A 3 Grammar focus-4c,The present perfect tense,现在完成时,现在完成时的学习目标,1.现在完成时的定义、构成、用法（理解、掌握）,2.现在完成时标志词（理解、掌握）,4.注意短暂性动词与一段时间连用时的变化（难点）,3.区分现在完成时与一般过去时（重点）,now,past,future,一般过去时,现在完成时,定义：用来表示之前已经发生或完成的动作或状态，而其结果却和现在有联系: 动作或状态发生在过去,但它的影响现在还存在。,主要的两种

2、用法： 1.过去某一时间点发生的动作对现在产生影响。 2.过去某一时间点发生的动作持续到现在或还将持续下去。,Grammar Focus,The present perfect tense,助动词 （可以帮助构成肯定句、疑问句和否定句）助动词要和主语的人称、数保持一致。,现在完成时的谓语构成,句式结构： 1. 肯定句：主语 + have / has + 过去分词 (+ 其他) 2. 否定句：主语 + have / has + not + 过去分词(+ 其他) 3. 一般疑问句：have/ has + 主语 + 过去分词(+ 其他) 4.特殊疑问句：特殊疑问词 + have / has + 主语

3、+ 过去分词 (+ 其他),过去式和过去分词的变化相同 规则变化： 1. 一般在动词词尾直接加ed。 2. 以不发音的e结尾的动词后面加d。 3. 以“辅音字母 + y”结尾的动词，变y为i， 再加-ed。 4. 以“元音字母 + y”结尾的动词，直接加-ed。 5. 词尾只有一个辅音字母的重读闭音节动词，要双写辅音字母，再加-ed。,不规则变化： 1. A A A型： let let let; 2.A B B型： feel felt felt; 3.A B C型： drink drank drunk 4.A A B型： beat beat beaten 5.A B A型： come came

4、 come,What are the key words for the Present Perfect Tense?,Key words,yet,ever,never,since,for,just,before,already,so far,in the past 10 years,twice,也可以是其他表示时间、次数的词,how long,4a Use the words in brackets to complete the conversations. 1. A: Would you like something to drink? B: No, thanks. _. (just/

5、drink some tea) 2. A: I heard you lost your key. _? (find) B: No, not yet.,I have just drunk some tea,Have you found it,3. A: Do you know when Tom is leaving? B: _. (already/ leave) A: When _? (leave) B: This morning. 4. A: Is your sister going to the movies with us tonight? B: No. _. (already/ see

6、the film),He has already left,did he leave,She has already seen the film,5. A: What do your parents think about our plan? B: I _. (not/ tell them/yet),havent told them yet,1. 侧重点不同 现在完成时和一般过去时所表示的动作都发生在过去，但它们所强调的重点不同： 现在完成时侧重于对现在的影响;而一般过去时侧重于某一动作发生在过去某个时间或某段时间，即现在完成时侧重于现在的结果。 一般过去时侧重于动作发生的时间。,现在完成时与

7、一般过去时区别,2. 时间状语不同 现在完成时常与already， yet， just， ever， never， before等副词以及“for+段时间”，“since+过去时间/从句”等时间状语连用; 一般过去时则常与“一段时间+ago”，just now， yesterday， last week等表示过去时间的状语连用。,现在完成时与一般过去时区别,用括号中所给词的适当形式填空。 1.I _ ( join) the book club last month and I _ (read) five books already. 2.I only _ (start) taking Engl

8、ish classes last week and I _ (learn) 50 English words already. 3. - When _ she _ (leave)? - Two hours ago.,joined,have read,started,have learned,did leave,4. Tony _ (buy) a pop music CD yesterday, but he _ (not listen) to it yet. 5.Myfather_just_(come)backfromwork. Heistirednow. 6. She _ (see) the

9、newspaper on the table this morning, but she _ (not have) anytime to read it yet.,bought,hasnt listened,has come,saw,hasnt had,4b Fill in the blanks with the correct forms of the words in the brackets. Sally _ (love) reading. In the morning she reads the newspaper and in the evening she reads books.

10、 She _ already _ (read) more than 100 different books. Her favorite kind of books is science fiction. She is interested in science and technology and loves to imagine what the world _ (be) like in 50 years.,loves,has,read,will be,She _ (finish) reading a book about robots last week and _ (write) a b

11、ook report about it next week for her French class. Every time she is in the library, Sally looks at the many books she _ (not read) yet and she cant wait to read them.,finished,will write,hasnt read,短暂性动词与时间段的关系,短暂性动词在肯定句、疑问句中不能与时间段连用。,为了表述这种意思,我们常用相应的 延续性动词 来代替短暂性动词。,Some verbs cant often be used

12、with for or since,Some verbs cant often be used with for or since,die have/has been dead,Please point out any mistakes and correct,She has bought the computer for two years.,had,Please point out any mistakes and correct,How long have you come to the United States？,been in,Please point out any mistak

13、es and correct,I have borrowed the dictionary since 3 days ago .,kept,Please point out any mistakes and correct,The film has begun for 10 minutes.,been on,Please point out any mistakes and correct,The concert has finished for half an hour.,been over,Please point out any mistakes and correct,His dog has died for two years .,been dead,4c Complete the chart with information about you and your friend.,A: What books have you already read? B: I have already read Tom Sawyer and Harry Potter. A: What do you think of the