before连词用法及例句、句型.（没拿课本…哭…）

efore 在英语中是一个比较常用的虚词,它既可作介词或副词用,也可作从属连词用.在近几年的高考试题中常常出现考查其从属连词用法的题目.下面就把 before 作从属连词的用法归纳如下：1.表示“在……之前就……”.例如：Mary had finished her homework before her mother returned.在她妈妈回来之前玛丽就已经完成了作业.2.表示“过了多久后才……；动作进行到什么程度才……”.例如：The man almost knocked me down before he saw me.那个男人差点把我撞倒才看见我.They walked about 30 miles to the west before they saw a village.他们西行了大约 30 英里才看见一个村庄.They worked day and night about three days before everything returned to normal.他们日夜工作了大约三天,一切才恢复正常.3.表示“来不及；尚未……就……”.例如：Before I could get in a word,he had measured me.我还没来得及插话,他就已经给我量好了尺寸.He ran off before I could stop him.我还没来得及阻止他,他就已经跑了.She left the company before I could have a word with her.我还没来得及和她打声招呼,她就已经离开了.4.表示“刚……就……”.例如：I had hardly sat down before the bell rang.我刚坐下铃就响了.5.表示“不知不觉就……；还没弄清就……”.例如：Time passed quickly and three months went by before Aqiao knew it.时间过得很快,不知不觉阿巧已经度过了三个月.6.表示“宁愿……,决不……；与其……,毋宁……”,常与 will 或 would 连用.例如：I would die before I would tell.我宁死不说.I'd shoot myself before I apologized to him.我宁死也不向他道歉.I would / will die before I surrender.我宁死不屈.7.表示“否则；以免”.例如：Do it now before you forget.现在就做,免得忘了.I'll write it down before I forget it.我得记下来以免忘了.8.用于句型“ It was + 时间段 + before ...”,表示“过了多久才……”.例如：It was three days before he came back.三天后他才回来.9.用于句型“ It was not long before ...”,意为“不久就……”.例如：It was not long before he sensed the danger of the position.不久他就意识到了处境的危险.10.用于句型“ It will be (not) + 时间段 + before ...”,表示“要过多久／不久……才……”.例如：It will be half a year before you graduate from this school.半年后你才能从这所学校毕业.It will be not long before you find you are wrong.不用多久你就会发现你是错的.