七 关于现在完成时 （have/has done ）
表示过去发生的动作对现在造成的影响或产生的结果； 过去的动作一直持续到现在刚刚停止，或还会继续进行下去。常与延续性动词连用。完成时常与lately， so far， recently， up to/until now， in the past/last few years， for some time， since some time ago， since + clause 连用。
I have finished reading three books so far.
常用句式：
1 It is /has been some time since + clause （ did）
2 This/It is the first time that + clause （ have done）
3. This is the best film that + clause （ have done）
注意：一般过去时与现在完成时的区别：
一般过去时只表示过去的动作，常与过去的具体时间（包括when）连用； 现在完成时则强调对现在的影响或结果。要特别注意时间状语。
He finished the work three hours ago.
Three years have passed since he came to China.
八 关于过去完成时 （had done sth）
表示在过去某一时刻或动作之前已经完成的动作。不能单独使用。
（1）It was three years since he had come here.
It/That was the first time that+ clause （ had done）
This was the best film that + clause （ had done）
（2） had hoped/expected/planned/wanted/meant/thought …表示过去未曾实现的愿望或打算。
We had hoped to catch the 7：00 train， but we missed it.
（3） No sooner /Hardly had +S.+ p.p than/when + clause （ did）
No sooner had we arrived home than it began to rain.
（4） By the end of + 过去时间
（5） By the time + clause （ did）
By the end of last term， they had finished two thirds of the task.
By the time he was ten， he had built his own lab.
注意： by the end of + 将来时间，by the time + clause （do/does） 与将来完成时连用。
By the time he comes back we will have finished the work.
By the end of this year the project will have been completed.
九 完成进行时 （have/has been doing sth.， had been doing sth）
现在完成进行时表示过去的动作一直持续到现在刚停止或还会持续下去。与延续性动词连用。介词常用for 和since . 过去完成进行时表示在过去某一时刻或动作之前一直进行的动作。没有被动形式， 被动式用完成时代替。
He has been doing the maths problems since 8：00.
They had been watching TV before I came back.
十 关于时态的呼应
一般说来，主句为现在时或将来时，从句视情况而定； 如果主句动词为过去时，从句则必须用过去时（ 客观真理、自然现象除外）。
She doesn’t know you have been in Dalian for three years.
He has told me when you will begin the new plan.
She doesn’t know why her father didn’t come back yesterday.
注意：如果从句中有过去的具体时间，即使动作在主句动词之前发生，也仍用一般过去时。
He said he went to school when he was five years old.
She told me she went abroad in 1999.
十一 关于被动语态 （ 只有及物动词才有被动语态）
1.各种时态被动语态的构成：
一般现在时/一般过去时：be （ am/is/are/was/were） + done
一般将来时/过去将来时：will（would）/shall（should）/be going to be done
现在完成时/过去完成时：have/has/had been done
现在进行时/过去进行时：be being done
注意：be也可以用get （ 有时也用become）表示，常用语口语。 疑问否定借助do/does/did
The boy gets punished almost every day.
Did you get scolded yesterday？
2. 含有情态动词的被动语态构成：must/may/can/could/might be done
The work must be finished as soon as possible.
3. 动词短语的被动语态，注意动词后的介词
The old couple are being taken good care of.
4. 感官动词后做宾补的不定式，变被动时省略的to要加上。
We saw him cross the road. → He was seen to cross the road.
5. 关于主动形式表达被动含义。
（1） 当不定式的逻辑主语与句子主语相同时，不定使用主动形式。
I have many questions to ask.
With many work to do tonight， I have to stay at home.
（2）sth/sb.+ adj. + to do
This kind of food is crisp and tasty to eat.
The young man is easy to get along with.
（3） sth/sb need/want/require doing （=to be done）
be （well） worth doing
The flowers need/want/require watering/tobe watered.
The old man need examining.
（4） be to blame 受责备
Who is to blame for the accident？
6. 某些系动词如：feel， taste， smell， sound. Look， turn， prove等，以及一些表主语品质、性能的词，如：sell， read， wash， write， clean， burn， record 等没有被动形式。
The room cleans very easily.
The fruit tastes good and sells well.
Dry wood burns easily.
The cloth washes well.
The pen writes smoothly.
His voice records well.
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