仁愛版英語八年級(jí)下冊(cè)全冊(cè)語法復(fù)習(xí).ppt課件

1、時(shí)間狀語從句When/while/before/after/until/as soon as+一個(gè)完整的句子構(gòu)成“時(shí)間狀語從句”注意幾點(diǎn)：一、 when/while 的區(qū)別1.when表示主從句兩個(gè)動(dòng)作同時(shí)發(fā)生或先后發(fā)生。而while表示主從句兩個(gè)動(dòng)作同時(shí)發(fā)生或強(qiáng)調(diào)主句的動(dòng)作在從句動(dòng)作進(jìn)行期間發(fā)生。(1)_ they are waiting for the New Year, they listen to music , sing songs and dance.(2)_ the boy saw his mother, he stopped crying.WhileWhen2. when+短暫

2、性動(dòng)詞或延續(xù)性動(dòng)詞 while+延續(xù)性動(dòng)詞(1)He was doing his homework _ I saw him.(2)_she was singing, we all lost ourselves in her beautiful voice.(3)She was cooking _ someone knocked at the door.3.進(jìn)行時(shí)+while+進(jìn)行時(shí)She was dancing _ I was singingwhenWhen/whilewhenwhile二、when從句的謂語動(dòng)詞可以在主句謂語動(dòng)作之前、之后或同時(shí)發(fā)生；while和as從句的謂語動(dòng)作必須是和主句

3、謂語動(dòng)作同時(shí)發(fā)生。 1從句動(dòng)作在主句動(dòng)作前發(fā)生，只用 when。 When he had finished his homework，he went to bed at once（finished先發(fā)生） When I arrived at the airport，the guests had left (客人)（arrived at 后發(fā)生）2. when從句動(dòng)詞為瞬間動(dòng)詞時(shí)，不能由while替換。如： When he came yesterday, we were playing basketball.昨天他來時(shí)，我們正在打籃球。 三、as引導(dǎo)的時(shí)間狀語從句表示“當(dāng)時(shí)”“一邊一邊”，指主句

4、的動(dòng)作和從句的動(dòng)作同時(shí)發(fā)生，既可以表示一段時(shí)間也可以表示一點(diǎn)時(shí)間。 As the time went on，the weather got worse隨著時(shí)間的推移，天氣變得越來越糟糕 He jumps as he goes along. 他邊走邊跳。The little girls sang as they went小姑娘們一邊走，一邊唱。 四、before引導(dǎo)的時(shí)間狀語從句表示表示的動(dòng)作發(fā)生在主句動(dòng)作之后。My father booked the room before we arrives.He worked in Hangzhou before he came here.after引導(dǎo)

5、的時(shí)間狀語從句所表示的動(dòng)作發(fā)生在主句動(dòng)作之后After they parked their bikes, they went to Tianan men square.I will call you after I finish the work.五、 until “直到” notuntil直到才如果主句中的謂語動(dòng)詞是瞬時(shí)動(dòng)詞時(shí)，必須用否定形式；如果主句中的謂語動(dòng)詞是延續(xù)性動(dòng)詞時(shí)，用肯定或否定形式都可以，但表達(dá)的意思不同。He waited until it was 12 oclock.He didnt go home until it was 12 oclock.I worked until

6、 he came back.我工作到他回來為止。 I didnt work until he came back.他回來我這才開始工作。六、as soon as as soon as.可譯為一就，用來表示主從句的動(dòng)作是緊接著發(fā)生的。eg. He will come and see you as soon as he can. 他一有空就來看你。 He rushed home as soon as he got the good news.他一得到這個(gè)好消息就奔回家。If 引導(dǎo)的條件狀語從句Revision_selfcheck位置：從句可放在主句之前或之后，但是放在主句之前須有逗號(hào)隔開eg:如果

7、我有足夠的錢，我就去環(huán)游世界If 引導(dǎo)條件狀語從句 定義：if “如果, 假如” 它引導(dǎo)的句子表示某事發(fā)生所需的條件，即“在條件下，某事才能發(fā)生”，在句子中充當(dāng)狀語，因此稱之為條件狀語從句。（ If引導(dǎo)的條件狀語從句表示假如有從句的動(dòng)作發(fā)生，就會(huì)有主句動(dòng)作的發(fā)生 ）If I have enough money, I will travel around the world =I will travel around the world if I have enough moneyIf條件句：條件句用于陳述語氣，表示假設(shè)的情況可能發(fā)生，其中 if 是“如果”的意思。 主句一般將來時(shí) ，從句用一般

8、現(xiàn)在時(shí)。 構(gòu)成條件從句主句時(shí)態(tài)If一般現(xiàn)在時(shí)主語shall/will+動(dòng)詞原形例句If he comes,he will take us to the zoo.用法：1. 如果主句是一般將來時(shí)，從句則用一般現(xiàn)在時(shí)。 If it rains（從句）， I will stay at home. Ill go with you if you dont want to go alone（從句）. 2.如果主句含有must, may, can 等情態(tài)動(dòng)詞，從句也要用一般現(xiàn)在時(shí)。 If you drive too fast, you may have an accident. You must stop

9、if the traffic is red. If you finish the homework， you can go home 如果你作業(yè)做完了就可以回家了。 If you want to lose weight you must/should eat less bread. 如果你想減肥，你必須少吃面包。3. 如果主句是祈使句，從句同樣要用一般現(xiàn)在時(shí)。Dont go and play football if you dont finish your homework.Please call me if he comes next Sunday.練一練：1。如果她早點(diǎn)兒起床，就有時(shí)間在家

10、里吃早餐 If she_ _a little earlier, shell have time to eat breakfast at home.2。如果你參加聚會(huì)，你將會(huì)過得很開心。If you_ the party ,you_ _ a great time.3。如果明天下雨，我們將不去野餐If it _tomorrow, we _ _ for a picnic.4。如果你經(jīng)常聽英文歌，你將會(huì)喜歡英語If you often _ _English songs, you_ _English.gets upjoin will haverains wont golisten to will lik

11、e當(dāng)賓語從句表示不確定或疑問時(shí)，由if或whether引導(dǎo)，表示“是否、是不是、能否”等。例如：我想知道他是否住這兒。I want to know if (whether) he lives there.他問我能否幫他。He asked me whether (if) I could help him.4）不能用if，只能用whether的四種情況：a. 在介詞后Im thinking of whether we should go fishing.b. 直接與or not連用時(shí)I dont know whether or not they will come to help us.c. 在動(dòng)

12、詞discuss后面的賓語從句中We discussed whether we would have a sports meeting next week.d. 賓語從句提前時(shí)只能用whetherWhether this is true or not, I cant say.難點(diǎn)鏈接單音節(jié)及部分雙音節(jié)形容詞比較級(jí)（- er）和最高級(jí)（- est）的規(guī)則變化。1. 一般在詞尾直接加er/est: fastfasterfastest2. 以e 結(jié)尾的單詞去e加er/est: latelaterlatest3. 以輔音字母加y結(jié)尾的單詞，把y改成i, 再加 er/est : earlyearlier

13、earliest4.部分雙音節(jié)詞以及所有三音節(jié)詞，比較級(jí)加more，最高級(jí)加most：more slowly，most slowly more carefully，most carefully有些副詞的比較等級(jí)變化是不規(guī)則的。常見的有：原級(jí)比較級(jí)最高級(jí) wellbetterbestbadlyworseworstmuchmoremostlittlelessleastfarfarther / furtherfarthest / furthest副詞比較等級(jí)的用法He didnt dance so(as) well as Jim. 他跳舞沒有吉姆跳得好a. 同級(jí)比較：表示兩者在某一方面程度相同時(shí)，用

14、“as+副詞原形+as”的句式；但表示前者不如后者時(shí)，用“not so(as)+副詞原形+as”的句式。如；The boys are listening as carefully as the girls. 男生們跟女生們?cè)谝粯诱J(rèn)真地聽。b.比較級(jí)： My brother did much better in his lessons than I. 我哥哥功課學(xué)得比我好多了。表示一方程度比另一方更高時(shí)，用“副詞比較級(jí)+than”的句式。在這一句式中，當(dāng)than前后的動(dòng)詞相同時(shí)，通常用助動(dòng)詞代替后面的動(dòng)詞。該動(dòng)詞或助動(dòng)詞可以省略。副詞比較級(jí)前常用much., a little, still, even表示“更”，這也可以作為判斷比較級(jí)的依據(jù)。如： I sing better than she (does). 我唱歌比她唱得好。c.最