1、Chapter 1 語(yǔ)法If 和 unless引導(dǎo)的條件狀語(yǔ)從句我們用 if 引導(dǎo)的條件狀語(yǔ)從句來(lái)討論可能的條件以及該條件成立時(shí)可能的結(jié)果。一 . 學(xué)習(xí) if 引導(dǎo)的條件狀語(yǔ)從句的用法，我們可先從如下的口訣入手：If 條件句不一般，幾個(gè)要點(diǎn)記心間；條件句，放在前，逗號(hào)要句中間條件句表可能，主句多用將來(lái)時(shí)；條件句表事實(shí)，主句常用現(xiàn)在時(shí)。We can walk there if we cantfind a bus. 如果我們找不到公車(chē)，也能走路去那里主句條件狀語(yǔ)從句If it rains tomorrow, we will not go to the zoo. 如果明天下雨，我們就不去動(dòng)物園條件狀

2、語(yǔ)從句主句What will you go if you find someone in danger?主句條件狀語(yǔ)從句如果你發(fā)現(xiàn)某人有危險(xiǎn)，你會(huì)怎么做？If 條件句有不同的類型，簡(jiǎn)述如下：1. 用 if 條件句表達(dá)客觀真理或普通現(xiàn)象If 條件句用于表達(dá)客觀真理或普通現(xiàn)象時(shí)，主，從句時(shí)態(tài)均用一般現(xiàn)在時(shí)，如：Eg. If you freeze water, it turns into ice.A fish dies if you take it out of water.2. 用 if 條件句表示將來(lái)可能發(fā)生的事情在表示將來(lái)可能發(fā)生的事情的if 條件句中，主句用一般將來(lái)時(shí)，而if 從句用一般現(xiàn)在

3、時(shí)表示將來(lái)的時(shí)間，即主將從現(xiàn)Eg. If I like the house, I will buy it.如果我喜歡這房子，我就會(huì)把它買(mǎi)下I will tell her if I see her. 如果我見(jiàn)到她，我就會(huì)告訴她。主句中的 will 也可以用情態(tài)動(dòng)詞can, may 或 might 等代替。如：Eg. If they are friendly ， I might invite them to the party. 如果他們很友善，我可能會(huì)請(qǐng)他們?nèi)⒓泳蹠?huì)If we hurry now, we can stop for coffee later. 如果我們現(xiàn)在抓緊時(shí)間，就可以稍后1去

4、喝咖啡注意：在條件句中，主句部分只能使用動(dòng)詞will 的一般將來(lái)時(shí)，不能使用 be goingto 的結(jié)構(gòu)二 . Unless 的條件句表示在特定條件下，才決定做或不做一件事，中文用的連接詞一般是“除非”和“否則”。如：除非刮臺(tái)風(fēng)，否則演唱會(huì)將如期進(jìn)行。 在英語(yǔ)中，我們可以用 unless表達(dá)這個(gè)意思，相當(dāng)于if not 。以這個(gè)句子為例：The concert will be held as schedule unless there is a typhoon.= the concert will be held as schedule if there is not a typhoonSh

5、e will keep on singing unless she is told to stop.她會(huì)一直唱下去，除非有人叫她停止= she will keep on singing if she is not told to stop也可以用 or(否則 ) 來(lái)做同義句轉(zhuǎn)換Unless you listen carefully, you wontknow the answer.= if you dontlisten carefully, you wontknow the answer.= you should listen carefully, or you wontknow the an

6、swer.2深圳中考題：1.If I _ his phone number, I will tell you.A. findB. foundC. will findD. have found2.We will go camping if it _ tomorrow.A. Won t rainB. didn t rain C. doesn t rain D. isn t raining3.I m waiting for my friend. If he _, I _ swimming alone.A. doesn t come; will goB. won t come; will goC.wi

7、ll come; won gotD. don t come; will go4._ you go to the supermarket at 7 p.m, you can buy a lot of cheap food.A. IfB. UnlessC. WhetherD. When5.I won t get to the party on time _ I catch the first train tomorrow morning.A. IfB. UnlessC. WhetherD. When6. -Shall we go on a picnic this weekend?-Good ide

8、a! Unless it _.A. rainsB. doesn t rainC. rainD. won t rain7. -Can I change the jacket for another one _ itdoesn t fit me well?- Of course.A. unlessB. ifC. thatD. though8.Nobody can learn maths wellhe works hard on it.A ifB unlessC thoughtD however9.If fishaway from water, theydie.A are taking, won t

9、B are taken, willC are being taken, willD take, wont10. Each student can ask teachers for help if hehow to work out theproblem.A will knowB won t knowC don t knowD doesn t know3誠(chéng)信篤行勤奮一A 用 if 或 unless 填空1.he wants to see me, you can tell him to wait.2.it snows tomorrow, we ll have a day or two off.3.

10、We wontgo to his partyhe invites us.4.She is sure to pass the examinationshe is ill.5.Ill take that computerI have enough money.6.my grandma wears glasses, she can see better.7.I won tbuy that backpackit costs less than $208.Im tired; I ll have a rest for tea.9.You won tget paid for time offyou have

11、 a doctor s note.10. you will get a toothacheyou do clean your teeth regularly.B 用所給單詞的適當(dāng)形式填空1.If he(get) a low mark in the test, he(study) harder.2.If you(swim) every day this summer, you(be) very healthy .3.If he(not hurry), he(not see) the beginning of the match.4.You cantgo out unless you(finish

12、) your homework.5.Unless I save my money carefully, I(not be) able to buy a football.6.If it(not rain) tomorrow, we(go) to the park.7.If he(return) to the school, I(let) you know.8.Hesmoking unless he(have) enough money.9. They can remember it better if someone(give) them some adviceabout it.10. The man(set off) i