教育精品：before用法小结.ppt
Before 用作连词，其基本词义是用作连词，其基本词义是“在在-之前之前”，用来表示时间或顺序。如：，用来表示时间或顺序。如：Turn the light off before you sleep.睡前先把灯熄掉睡前先把灯熄掉Think before you speak.说话之前应先想清楚说话之前应先想清楚但在不同的语境中但在不同的语境中before 有不同的翻译有不同的翻译1.Before 表示表示“不等不等-就就-/尚未尚未-就就-”.-why didnt you tell him about the meeting?-He rushed out of the room _ I could say a word.(我还没来得及说他就冲出了房间我还没来得及说他就冲出了房间)A.before B.until C.when D.afterbefore._ I could get in a word,he had measured me.我还没来得及插上话，他就给我量好了尺寸我还没来得及插上话，他就给我量好了尺寸 A.After B.When C.since D.before2.Before 表示表示“不知不觉，还没弄清就不知不觉，还没弄清就-”此意常用于此意常用于 before sb.know/realise-Time passed quickly and three months went by before I knew it.(时间飞快流逝，不知不觉时间飞快流逝，不知不觉3个月过去了个月过去了)Several weeks had gone by before I realised it.(不知不觉几个周就过去了不知不觉几个周就过去了)3.Before 表示表示“趁趁-还没还没”Its cloudy.Take an umbrella before You regret it.(带把伞吧带把伞吧 以免后悔以免后悔)Ill call him before I forget.(趁着还没忘记我就给他打个电话趁着还没忘记我就给他打个电话)Put that away before it gets broken.(把它收好，以免砸了把它收好，以免砸了)4.Before 用于这两个句型：用于这两个句型：It was/wasnt+一段时间一段时间+before 从句从句（过了多久（过了多久/没过多久没过多久才才-）一般过去时一般过去时 It will/wont+一段时间一段时间+before 从句从句 （还得过多久（还得过多久/用不了多久用不了多久就就-）一般现一般现在时在时区别：区别：It is+一段时间一段时间+since 从句从句It is+一段时间一段时间+since 从句（自从从句（自从有有多久了）（从句用一般过去时）多久了）（从句用一般过去时）It was+一段时间一段时间+since从句（自从从句（自从 有多久了）（从句用过去完成时）有多久了）（从句用过去完成时）巩固性练习巩固性练习1.A scientist must practise a lot _he can use all data tools well.A.as soon as B.when C.until D.before2._ she realized what was happening,she was hit over the head.A.When B.before C.since D.asBD3.why didnt you help the little boy?-Oh,sorry.He had struggled to his feet_ I ran over.A.until B.after C.before D.since4.He made a mistake,but then he corrected the situation _it got worse.A.until B.when C.before D.asCC5.Scientists say it may be 5 years_ it is possible to test this medicine on human patients.A.Since B.after C.before D.when6.Someone called me up in the middle of the night,but they hung up _ I could answer the phone.A.as B.since C.while D.before CD7.Youd better give it up _ it is too late as its very dangerous.A.before B.as C.when D.since8.It would be months _ he was fit for work.A.until B.since C.before D.afterAC9.It was evening _ we reached the little town of Winchester.A.that B.until C.since D.before10.The scientists had tried out many kinds of chemicals _ they found the right one.A.since B.after C.before D.whenDC
