11. 动词的时态
11.1 一般现在时的用法
1) 经常性或习惯性的动作，常与表示频腮度的时间状语连用。
时间状语： every…, sometimes, at…, on sunday
i leave home for school at 7 every morning.
2) 客观真理，客观存在，科学事实。
the earth moves around the sun.
shanghai lies in the east of china.
3) 表示格言或警句中。
pride goes before a fall. 骄者必败。
注意：此用法如果出现在宾语从句中，即使主句是过去时，从句谓语也要用一般现在时。
例：columbus proved that the earth is round..
4) 现在时刻的状态、能力、性格、个性。
i don't want so much.
ann wang writes good english but does not speak well.
比较：now i put the sugar in the cup.
i am doing my homework now.
第一句用一般现在时，用于操作演示或指导说明的示范性动作，表示言行的瞬间动作。再如：now watch me, i switch on the current and stand back. 第二句中的now是进行时的标志，表示正在进行的动作的客观状况，所以后句用一般现在时。
11.2 一般过去时的用法
1）在确定的过去时间里所发生的动作或存在的状态。
时间状语有：yesterday, last week, an hour ago, the other day, in 1982等。
where did you go just now?
2）表示在过去一段时间内，经常性或习惯性的动作。
when i was a child, i often played football in the street.
whenever the browns went during their visit, they were given a warm welcome.
3）句型：
it is time for sb. to do sth "到……时间了" "该……了"
it is time sb. did sth. "时间已迟了" "早该……了"
it is time for you to go to bed. 你该睡觉了。
it is time you went to bed. 你早该睡觉了。
would (had) rather sb. did sth. 表示'宁愿某人做某事'
i'd rather you came tomorrow.
4) wish, wonder, think, hope 等用过去时，作试探性的询问、请求、建议等。
i thought you might have some. 我以为你想要一些。
比较：
一般过去时表示的动作或状态都已成为过去，现已不复存在。
christine was an invalid all her life.
(含义：她已不在人间。)
christine has been an invalid all her life.
(含义：她现在还活着)
mrs. darby lived in kentucky for ven years.
(含义：达比太太已不再住在肯塔基州。)
mrs. darby has lived in kentucky for ven years.
( 含义：现在还住在肯塔基州，有可能指刚离去)
注意： 用过去时表示现在，表示委婉语气。
1）动词want, hope, wonder, think, intend 等。
did you want anything el?
i wondered if you could help me.
2）情态动词 could, would.
could you lend me your bike?
11.3 ud to / be ud to
ud to + do："过去常常"表示过去习惯性的动作或状态，但如今已不存在。
mother ud not to be so forgetful.
scarf ud to take a walk. (过去常常散步)
be ud to + doing： 对……已感到习惯，或"习惯于"，to是介词，后需加名词或动名词。
he is ud to a vegetarian diet.
scarf is ud to taking a walk.(现在习惯于散步)
典型例题
---- your phone number again? i ___ quite catch it.
---- it's 69568442.
a. didn't b. couldn't c. don't d. can't
答案a. 本句虽没有明确的时间状语，但从语意上看 出，在听的时候没有听懂这个动作发生在过去，因此应用过去时。
11.4 一般将来时
1) shall用于第一人称，常被will 所代替。
will 在陈述句中用于各人称，在争求意见时常用于第二人称。
which paragraph shall i read first.
will you be at home at ven this evening?
2) be going to +不定式，表示将来。
a. 主语的意图，即将做某事。
what are you going to do tomorrow?
b. 计划，安排要发生的事。
the play is going to be produced next month。
c. 有迹象要发生的事
look at the dark clouds, there is going to be a storm.
3) be +不定式表将来，按计划或正式安排将发生的事。
we are to discuss the report next saturday.
4) be about to +不定式，意为马上做某事。
he is about to leave for beijing.
注意：be about to 不能与tomorrow, next week 等表示明确将来时的时间状语连用。
11.5 be going to / will
用于条件句时， be going to 表将来
will 表意愿
if you are going to make a journey, you'd better get ready for it as soon as possible.
now if you will take off your clothes, we will fit the new clothes on you in front of the mirror.
11.6 be to和be going to
be to 表示客观安排或受人指示而做某事。
be going to 表示主观的打算或计划。
i am to play football tomorrow afternoon. (客观安排)
i'm going to play football tomorrow afternoon. (主观安排)
11.7 一般现在时表将来
1）下列动词：come, go, arrive, leave, start, begin, return的一般现在时表将来。这主要用来表示在时间上已确定或安排好的事情。
the train leaves at six tomorrow morning.
when does the bus star? it stars in ten minutes.
2）倒装句，表示动作正在进行，如：
