He said that he would have another try if he had the chance.
I knew he could help me if he was free the next day.
主要标志有：if 、unless 、until、 when 、as soon as

考点名称：过去将来时

• 过去将来时：
  表示从过去的某一时间来看将来要发生的动作或存在的状态。过去将来时常用于宾语从句和间接引语中。
  去将来时的出发点是过去，即从过去某一时刻看以后要发生的动作或状态。

• 过去将来时表达法：
  1. would+动词原形
    例如：When you asked Li Lei for help, he would never refuse you.
  2. was/were going to+动词原形
    例如：He told ustaht he was going to attend the meeting.
  3. was/were to+动词原形
    例如：Li Lei was to arrive soon.
  4. was/were about to+动词原形
    例如：We were about to leave there when it began to rain heavily and suddenly.
  5. was/were+现在分词
    例如：He was leaving the next day.

  句型结构：
  肯定句：主语+be（was，were）going to+动词原形～.
  否定句：主语+be（was，were）not going to+动词原形～.
  疑问句：Be（Was，Were）+主语+going to+动词原形～？
  
  肯定句：主语+would（should）+动词原形～.
  否定句：主语+would（should）not+动词原形～.
  疑问句：Would（Should）+主语+动词原形～？
  过去将来时的构成和一般将来时一样，只不过把助动词be变为过去式，把will，shall变为过去式。
  例句：I didn''t know if he would come. =I didn''t know if he was going to come. 我不知道他是否会来。

• 过去将来时具体用法：
  一、would+不定式
  1.用“would+不定式”表示过去将来时间通常带有表示过去将来的时间状语，而且多见于从属分句。
  He said he would come back the next day.
  2.如果要表示在过去将来某一时间正在进行得动作，可用“would+不定式进行体”。
  例如：He never imagined that some day he would be living away from his motherland.
  这种“would+不定式进行体”结构也可能仅仅表示一般过去过去将来时间，如同“will/shall+不定式进行体”表示一般将来时间一样。、
  例如：He told me that Mary would be coming the next day.
  如果要表示在过去将来某时以前业已发生得事态，可用“would+不定式完成体”。
  例如：The delegation would have arrived by four o'clock that afternoon.
  如果要表示从过去某时开始一直延续到过去将来某时得动作或事态，可用“would+不定式完成进行体”。
  例如： She said that by the end of May she would have been studying medicine for three years
  
  二、was/were going to +不定式
  用做表示过去将来，也通常带有表示过去将来时间得状语。
  例如： He said that he was going to live in the country when he retired.
  用做表示的动作或事态，也可以是没有实现的意图。
  例如：Last  Sunday we were going to go for a picnic but it rained .
  
  三、was/were to +不定式
  用做表示过去将来，通常指按过去的计划安排将在某个过去将来时间发生得事态。
  例如：They  were not to get away with it if they continued to violate the law.
  用作表示过去将来的安排，如果这个安排后来被取消了，没有实现，则用“was/were to +不定式完成体”表示，并可与表示现在、过去或将来得时间状语连用。 此外，其也可用作于表示以后不可避免得要发生得事件。
  例如：They said goodbye,little knowing they were never to meet again.
  
  四、was/were about to +不定式
  用半助动词be about to 的过去时形式也可使其表示过去将来。这种结构通常指最近的过去将来事态，而且在一定语境中通常指未曾实现的意图：
  例如：We were about to start when it began to rain .

  五、某些动词的过去进行时可表示过去将来时
  come,go,leave,arrive,start等严格按照时间表发生的表起止的动词可用过去进行时代替过去将来时。
  例1：He said the train was leaving at six the next morning.他说火车第二天早晨出发。
  例2：She told me she was coming to see me.她告诉我她要来看我。

  六、特定场合的一般过去时可表示过去将来时
  条件状语从句和时间状语从句中须用一般过去时代替过去将来时。
  例1：I didn't know when she would come, but when she came I would let you know.我不知道她什么时候来，但她来了我会告诉你。
  析：第一个when引导宾语从句，可使用将来时，第二个when引导时间状语从句，只能用一般过去时代替过去将来时。
  例2：I didn't know if she would come,but if she came I would let you know.我不知道她是否来，但如果她来我会告诉你。
  析：第一个if引导宾语从句，可使用将来时，第二个if引导条件状语从句，只能用一般过去时代替过去将来时。

考点名称：状语从句

• 状语从句：
  指句子用作状语时，起副词作用的句子。它可以修饰谓语、非谓语动词、定语、状语或整个句子。
  根据其作用可分为时间、地点、原因、条件、目的、结果、让步、方式和比较等从句。
  状语从句一般由连词(从属连词)引导，也可以由词组引起。
  从句位于句首或句中时通常用逗号与主句隔开，位于句尾时可以不用逗号隔开。

• 状语从句分类:
  1、时间状语从句
  常用引导词：
  when, as, while, as soon as, while, before, after, since , till, until
  特殊引导词：
  the minute, the moment, the second, every time, the day,the instant, immediately , directly, no sooner … than, hardly …when, scarcely … when
  I didn't realize how special my mother was until I became an adult.
  While John was watching TV, his wife was cooking.
  The children ran away from the orchard(果园) the moment they saw the guard.
  No sooner had I arrived home than it began to rain.
  Every time I listen to your advice, I get into trouble.
  
  2、地点状语从句
  常用引导词：
  where
  特殊引导词：
  wherever, anywhere, everywhere
  Generally, air will be heavily polluted where there are factories.
  Wherever you go, you should work hard.
  
  3、原因状语从句
  常用引导词：
  because, since, as, for
  特殊引导词：
  seeing that, now that, in that, considering that, given that, considering that, as much as, so much as
  My friends dislike me because I'm handsome and successful.
  Now that everybody has come, let's begin our conference.
  The higher income tax is harmful in that it may discourage people from trying to earn more.
  Considering that he is no more than 12 years old, his height of 1.80 m is quite remarkable.
  
  4、目的状语从句
  常用引导词：
  so that, in order that
  特殊引导词：
  lest, in case, for fear that,in the hope that, for the purpose that, to the end that
  The boss asked the secretary to hurry up with the letters so that he could sign them.
  The teacher raised his voice on purpose that the students in the back could hear more clearly.
  
  5、结果状语从句
  常用引导词：
  so that, so… that, such … that,
  特殊引导词：
  such that, to the degree that, to the extent that, to such a degree that,
  He got up so early that he caught the first bus.
  It's such a good chance that we must not miss it.
  To such an degree was he excited that he couldn't sleep last night.
  
  6、条件状语从句
  常用引导词：
  if, unless,
  特殊引导词：
  as/so long as, only if, providing/provided that, suppose that, in case that, on condition that
  We'll start our project if the president agrees.
  You will certainly succeed so long as you keep on trying.
  Provided that there is no opposition, we shall hold the meeting here.
  
  7、让步状语从句
  常用引导词：
  though, although, even if, even though
  特殊引导词：
  as(用在让步状语从句中必须要倒装),while ( 一般用在句首 ),no matter …, in spite of the fact that, while, whatever, whoever, wherever, whenever, however, whichever
  Much as I respect him, I can't agree to his proposal.
  尽管我很尊敬他, 我却不同意他的建议。
  The old man always enjoys swimming even though the weather is rough.
  No matter how hard he tried, she could not change her mind.
  He won't listen whatever you may say.
  
  8、比较状语从句
  常用引导词：
  as(同级比较), than(不同程度的比较)
  特殊引导词：
  the more … the more … ; just as …, so…; A is to B what /as X is to Y; no … more than; not A so much as B