Unit3TheComputerandtheInformationAge-grammar教案

　　时态一。总述： 为了便于讲解，我将英语中的时态，分为现在时和过去时。现在时包括一般现在时，现在进行时，现在完成时，姑且把将来时也归入此类。过去时包括，一般过去时，过去进行时，过去将来时，过去完成时。一般来说，时态对应是指现在时对应现在时，过去时对应过去时。当然，特殊语境需要特别分析。二。时态对应主要包括以下的典型用法。1。下列情况下，如果主句是将来时《用will/shall/can/must/》或者主句是祈使句，从句用一般现在时。1》在 if /unless/ even if/ 引导的条件状语从句中.如：you will be punished unless you go though with the work.i won't attend the party even if i am invited.2》在when/before/until<till>/as soon as/the moment/ once/引导的时间状语从句中。如：i'll let you know the moment i get timely information.once you realize your mistake, you'll regret for what you've done.3》在 no matter what/no matter who/no matter when/no matter where/no matter how/no matter which/或者 whatever/whoever/whenever/wherever/however/whichever 引导的让步状语从句中。如：i'll believe whatever you have said.however difficult the problem is ,we'll overcome it .wherever you go,i'll follow you.we can help whoever gets in trouble.2。在 祈使句+and/or+句子 的模式中，and/or 后的句子常用将来时态。如：put on the coat,or you'll catch a coldwork hard,and you'll make rapid progress.3。注意used to/would 区别。他们都表示过去常常。但would 常和时间连用，而used to 不可以。如：when i was a boy, i would swim every day.<不用used to>4.be about to do 如果用在简单句中，常用一般现在时。如果用在复合句中，常和when 引导的过去时的从句连用。如：i am about to leavewhen i was about to fall asleep when someone knocked the door.但要注意be about to do 不和具体的时间连用。我们不可以说，we are about to leave this afternoon ,应说，we are about to leave或者说，we will be leaving this afternoon.5.语境中的过去时常表示“刚刚，刚才”之意，暗示现在已经不是这样..如：sorry,i didn't know you were here .6.表示愿望，打算一类的词，如hope, expect, mean, intend, want, think, suppose, want 等，其过去完成时表示过去未曾实现的愿望或意图。如：----why haven't you attended the party?---i had meat to,but i was busy.7.在 it/this be the first/second/---time+that 句中。如果be 为一般现在时，that后的句子一般用现在完成时或一般现在时，如果  be为一般过去时，that后的句子为过去完成时。如：this is the first time that i have met the famous scientist.this is the first time that he gets involved in the tournament.8.在 it be +段时间 +since 从句中，如果be 表现为 is或has been 形式，since 从句用过去时，如果be 表现为was 或 had been,从句用过去完成时。如：it is 3 years since he has taught in this university.9.在...hardly...when/...no sooner...than...结构中，hardly/no sooner 所在的主句用过去完成时，when/than所在的从句用一般过去时。而且，如果 hardly/no sooner 放在句首，主句部分要部分到装，从句结构不变。如：i had  hardly recognized him when he turned up.hardly had i recognized him when he turned up.no sooner had the train left than i got to the railway station.10. 在“主句+before+从句”的结构中，如果主句和从句中动词先后顺序明显，主句用过去完成时，从句用一般过去时；如果主句和从句的动作先后顺序不明显，主从句都用一般过去时。如，the film had been on for 30 minutes before i got there .he hurriedly went out before i said a word.11.在" it be+段时间+before从句"中，如果从句是一般现在时，主句中的 动词用will be形式。如果从句中的动词是一般过去时，主句动词用 was的形式。如：it will not be some time before he graduates.it was 3 years before he graduated.12.在“will/shall be doing"结构中《将来进行时》，其后往往跟上具体的将来时间。如：the plane will be flying over the pacific this time tomorrow morning.13.在“by + 时间”的结构中，如果时间是过去时间，主句中的行为动词常为过去完成时，但如果句中的动词是状态动词be ,仍然用一般过去时。如果时间是将来时间，主句中的行为动词用将来完成时，同样，如果句中的动词是状态动词be,仍然用将来时。如：by the end of last year,they had completed the task.by last month,he was 10 years old.by he joined the army,he had served us as a cook for 5 years.by next month,we will have learned lesson 21.14.在“主语+介词+主语”的结构中，句中的动词要以第一个主语作为标准，这类介词有with/together with/as well as/等。如：the teacher together with the students is going to hongkong tomorrow.the dog ,as well as ten sheep is going to be shipped to qingdao .15.在   neither...nor.../either...or.../there be...等结构中，采用“就近原则”。如：were neither you nor he there when the accident happened ?neither you nor he was there when the accident happened.there is a pen and ten books on the desk.there are ten books and one pen on the desk.16.注意一般过去时 和 过去进行时的区别。一般过去时可以指过去动作的完成，而过去进行时仅表示动作的进行。如：---has he finished the book?---i've no idea, but he_____<write> it last week.a.wrote          b.was writing学生很容易选a。从 i've no idea仔细分析，可以知道本句的动作是进行，而不是完成。所以b是正确的。