一、非真实假设（真实假设一般遵循主将从现原则）

重点是背诵这张表

• 违背现在的事实
  例 .
  if I ( had )a pen,I( would lend) it to you.
  如果现在他知道你在这里，他肯定会来看你（译）
  if he knew you are here ,he would certainly come to see you

• 违背过去的事实
  例.
  if I (** had arrived** ) earlier,I ( **would have caught **) the train
  倘若不是下大雨，我肯定会出席你们的星期五下午召开的会议。
  if it hadn't rained)so heavily I would surely have come to your meeting on Friday afternoon

• 违背将来的事实（或将来不大可能发生的假设）
  例.
  if they (were to attack ) us,we(would wipe) them out.
  (虽有肯发生，但说话者主观上不希望发生）
  if he (should fail) ,I(would encourage) him to try again

• if 的省略。（倒装句）
  ——要将had,should,were 移到句首l

• 错综条件的虚拟语气
  ——不必遵循表格，只遵循自己所在表格中的时态
  例.
  要不是五月的那场干旱，我们今年可能夺得了大丰收（从句 过去，主句 将来 )
  if it (had not been) for the prolonged drought in May,we (should reap) a bumper harvest this year.

• 含蓄条件的虚拟语气（没有if ,主要是介词词组）
  例.
  (But for) the doctor's skill ,he (would have died)
  but for 要不是
  2.上下文
  Five minutes earlier ,and we (could have caught)the last train.

巩固训练.
假如校长来了，我们对他说什么呢？(译)
if he headmaster were to come，what would we say to him ?

二、建议，命令，要求型语气

用动词原型。
do (主动)
be done (被动)
例.
The teacher insisted that we ( ) in his office at 5 o'clock.
A.is B. would be C.are D.be
He gave the order that the result of experiment ( be rechecked )(recheck)

常见的表建议，要求型的词（I drop cards 我出牌）

巩固训练.

1. I suggested that the meeting ( B ) at the manager's office.
   A. hold B.be hold C.is held D.is to be held
   注：被动
2. 我要求他立刻回复我（译）
   I demanded that he give me reply at once.