江苏省东台市唐洋镇中学八年级英语下册《Unit 1 Past and present Grammar(Ⅱ)》学案（无答案） 牛津版.doc

unit 1 past and present grammar()学案【学习目标】1.能够在语境中正确运用现在完成时。2.运用现在完成时谈论发生在过去并与现在有联系的事情。 3.理解并运用常与现在完成时连用的时间表达方式。【重点难点】理解并运用常与现在完成时连用的时间表达方式。【预习指导】【自学探究】一、 预习p16/17，查字典，写出下列单词的意思,并且熟记他们。 1、already _ 2、yet _ 3、just _4、ever _ 5、never _ 6、before _二、完成课本p17练习。三、尝试着阅读下面的知识链接，看看是否可以理解。【知识链接】 现在完成时的未完成用法 1、定义：现在完成时的未完成用法指的是动作开始于过去某一时刻，一直延续到现在，或可能还要继续下去。例如：he has lived here since 1978. 自从1978年以来，他一直住在这儿。(动作起始于1978年，一直住到现在，可能还要继续住下去。) i have been in the army for more than 5 years. 我在部队已经呆了五年多了。(动作开始于5年前，一直延续至今，有可能还要继续下去。) 2、特点：此种用法的句中常需一个表示一段时间的状语(由since或for引导)，或表示与现在时刻相连的时间状语(如：up to now，so far到目前为止)等。 例如：i have heard nothing from him up to now. 到目前为止我没有他的任何消息。 注意：(1) 现在完成时的未完成用法只适用于延续性动词，不可用于终止性动词，即瞬间完成或延续时间很短的动词。如：come，go，arrive，leave，join，become，die等。 (2 ) 现在完成时常见两种句型： 主语have / has beenfor 短语/ since 短语 it is一段时间 since 从句例如： he has been in the league for three years. = it is three years since he joined the league. 他入团已三年了。请尝试着做以下的练习 1. i _ (work) here since i _ (move) here in 1999.2. -how long _ _ the smiths _(stay) here? - for two weeks.3. she _ (be) ill for three days.4. she_ (not read) this book before. 5. _ _ you ever _ (travel) on a train before? 3. a. for 和表示一段时间的词组连用。eg. for six hours/nine days/ two weeks/thirty yearsb. since 和表示过去某一时刻的词或词组连用，这是介词。eg. since nine oclock this morning / last summer/ three weeks ago/septembersince 还可以引导时间状语从句，表示“自从.以来”，这是连词。eg. 自从他出生以来，他就住在这儿。he has lived here since he was born. _ three months _ two weeks ago, _ 1998, _last sunday4、延续性动词和终止性动词的概念 英语中，动词按其动作发生的方式、动作发生过程的长短，可分为延续性动词和终止性动词。延续性动词表示能够延续的动作，这种动作可以延续下去或产生持久影响。如：learn, work, stand, lie, know, walk, keep, have, wait, watch, sing, read, sleep, live, stay等。 终止性动词也称非延续性动词、瞬间动词或短暂性动词，表示不能延续的动作，这种动作发生后立即结束。如open, close, finish, begin, come, go, arrive, reach, get to, leave, move, borrow, buy等。5、延续性动词的用法特征a. 延续性动词可以用于现在完成时，其完成时态可与表示段时间的状语连用。表示段时间的短语有：for two years, during the past three years, since last year, how long等。如：i have learned english since i came here.自从我来到这儿就学英语了。b. 延续性动词不能与表示短暂时间的点时间状语连用。如：it rained at eight yesterday morning.(误) rain为延续性动词，而at eight表示点时间，前后显然矛盾。如果用延续性动词表示一瞬间的动作，可以借助come, begin, get等终止性动词来表示。上句可改为：it began to rain at eight yesterday morning.(正)又如：-when did you get to know jack?-two years ago.-then youve known each other for more than two years.-thats right.6、终止性动词的用法特征a. 终止性动词可用来表示某一动作完成，因此可用于现在完成时。如：the train has arrived.火车到了。have you joined the computer group? 你加入电脑小组了吗？b. 终止性动词表示的动作极其短暂，不能持续。因此，不可与表示一段时间的状语连用(只限肯定式)。如：(1) 他死了三年了。误：he has died for three years.正：he has been dead for three years. 正：he died three years ago.正：it is three years since he died. 正：three years has passed since he died.(2) 他来这儿五天了。误：he has come here for five days.正：he has been here for five days. 正：he came here five days ago.正：it is five days since he came here. 正：five days has passed since he came here.(1)、(2)句中的die、come为终止性动词，不能与表示段时间的状语连用。那么，应如何正确表达呢？可以采用下面的四种方法：(1) 将句中终止性动词转换为相应的延续性动词，如上面两例中的第一种正确表达方式。下面列举几例：leavebe away from, borrowkeep, buyhave, begin/startbe on, diebe dead, move tolive in, finishbe over, joinbe in/be a member of, open sth.keep sth. open, fall illbe ill, get upbe up, catch a coldhave a cold。(2) 将句中表示段时间的状语改为表示过去确定时间的状语，如上面两例中的第二种正确表达方式。(3) 用句型it is+段时间+since.表达原意，如上面两例中的第三种正确表达方式。(4) 用句型时间+has passed+since.表达原意，如上两例中的第四种正确表达方式。3. 终止性动词可用于现在完成时否定式中，成为可以延续的状态，因而可与表示一段时间的状语连用。如：he hasnt left here since 1986.i havent heard from my father for two weeks.4. 终止性动词的否定式与until/till连用，构成not+终止性动词+until/till .的句型，意为直到才。如：you cant leave here until i arrive. 直到我到了，你才能离开这里。i will not go to bed until i finish drawing the picture tonight.今天晚上直到我画完画，我才上床睡觉。5. 终止性动词可以用于when引导的时间状语从句中，但不可以用于while引导的时间状语从句中。when表示的时间是点时间(从句谓语动词用终止性动词)，也可以是段时间(从句谓语动词用延续性动词)。而while表示的是一个较长的时间或过程，从句谓语动词用延续性动词。如：when we reached london, it was twelve oclock. (reach为终止性动词) please look after my daughter while/when we are away. (be away为延续性动词短语)6.终止性动词完成时不可与how long连用(只限于肯定式)。如：误：how long have you come here? 正：how long have you been here?正：when did you come here?【学习过程】step1: revision1. a guessing game.(using questions form of the ppt.)2. ask the ss to speak out some sentences with the ppt.step2: presentationtime expressionspresent the typical time expressions and their usages:already yet recently ever never for sincestep3: practice 1. ask the ss do the exercises and then check the answers.2. work in groups and learn how to use “for” and “since”, know the differences between them. 3. check the answers.(p17),and ask them to practice the dialo