257续：英语条件从句 类型1，2，3你有听过吗？

类型1条件从句

a 模型是：if...'+ 现在时... + will.

If it rains, the reception will take place indoors.

If we don't hurry, we'll miss the train.

The milk will go off if you leave it by the radiator.

表达一种开放式的条件，对于将要下雨还是不下雨的问题是吃开放态度的。我们一般不用 will 表达开放式的条件if it will rain这样表达是不对的。

注意

a 我们可以使用 will 在if从句中表达“结果“比主句中的将来还要将来

If it does/will do me more good, I'll take a different medicine.

b 我们可以用 shall 代替 will 放在I/we后面

If we don't hurry, we will/shall miss the train.

b 除了一般现在时，我们可以使用“现在进行时”或“现在完成时”

If we're having ten people to dinner, we'll need more chairs.

If I've finished my work by ten, I'll probably watch a film on TV.

除了will，我们也可以用“情态动词”或相似的表达放在主句里

If we miss the train, we can get the next one.

If Simon is hoping to borrow the car, he's going to be disappointed.

If you phone at six, they might be having tea.

也可以用“祈使语气”表将来

If you're going out, take your key. If you drink, don't drive.

c 现在时（包括现在进行时）在if条件句里可以表“现在”：

If you like tennis, you'll be watching Wimbledon next week, I suppose. If it's raining already, I'm definitely not going out.

d 我们也可以使用 will 在if从句中表“意愿”/“请求”，won’t表“拒绝”:

If everyone will help, we'll soon get the job done.—意愿

If the car won't start, I'll have to ring the garage.—拒绝

If you'll just take a seat, Mr Parsons will be with you in a moment.—请求

类型2的条件从句：

a 模型是： if...+ 过去时... + would.

If I had lots of money, I would/或should travel round the world.

If Phil lived nearer his mother, he would visit her more often.

I'd tell you the answer if I knew what it was.

这里过去时表是“虚拟条件” If I had lots of money 意思是我并不是真的有钱，我只是想象自己有钱的样子；我们不使用 would 来表达虚拟的条件 if I would have lots of money这种表达是错的

b 我们一般不混合“开放条件”和“虚拟条件”If I had lots of money, I will travel round the world.这种表达是错的

c 我们可以使用类型2表理论上的未来可能性.

If you lost the book, you would have to pay for a new one.

If we caught the early train, we'd be in Manchester by lunch time.

这里过去时表达一种想象中的未来动作（losing the book）.

试比较类型1和类型2的未来动作的可能性上的细微区别：

类型1: If we stay in a hotel, it will be expensive.-可能性是开放的（我们可能在酒店，也可能不会在酒店，可能性高）

类型2: If we stayed in a hotel, it would be expensive.-理论上的可能性，不太现实，住酒店可能性低

注意

类型2 表达要更礼貌和委婉一些

Would it be OK if 1 brought a friend? ~ Yes, of course.

Shall we go along the by-pass? ~ Well, if we went through the town centre, it would probably be quicker.

d 除了一般过去时，也可用进行时或could.

If the sun was shining, everything would be perfect. If I could help you, I would, but I'm afraid I can't.

除了would, 我们也可以使用情态动词could 或might放在主句里.

If I had a light, I could see what I'm doing.

If we could roll the car down the hill, we might be able to start it.

e 也可用would 放在if从句中表“请求”:

If you wouldn't mind holding the line, I'll try to put you through.

有时主句可以省略.：

If you'd just sign here, please.

我们也可以用 would like：

If you'd like to see the exhibition, it would be nice to go together.

5开放式条件与过去时

a 过去时的开放式条件自然是说过去.

Perhaps Mike took a taxi. ~ Well, if he took a taxi, he ought to be here by now. I used to live near the library. If I wanted a book, I went and got one/I would go and get one.

b 用类型2当做类型1的过去.

类型1: Don't go. If you accept the invitation, you will regret it.

类型2: I told you that if you accepted the invitation you would regret it. And now you are regretting it, aren't you?

c 也可结合“过去条件”和“未来结果”：

If they posted the parcel yesterday, it won't get here before Friday.

6 类型3 条件从句

a 模型是： if... + 过去完成... + would + 完成.

If you had taken a taxi, you would have got here in time.

If I'd phoned to renew the books, I wouldn't have had to pay a fine.

The man would have died if the ambulance hadn't arrived so quickly.

We'd have gone to the talk if we'd known about it.

(= We would have gone if we had known.)

这里过去完成表“虚拟”和想象的过去动作. Ifyou had taken a taxi 意思是你没有真的乘taxi.

不可以用“一般过去”或“完成时”在主句中. If you had taken a taxi, you got/had got here in time这样表达是错的

注意

Would have (或had have)不能用于if从句，除非在某些“非正式”场合=> If you'd have taken a taxi, you'd have got here on time.但是很多专业母语人士认为这种表达是错的.

b 我们可用 could + 完成时在 if从句中.

If I could have warned you in time, I would have done.

也可用情态动词could 或might+ 完成时在主句中.

If I'd written the address down, I could have saved myself some trouble.

The plan might not have worked if we hadn't had one great piece of luck.

注意

这里可以用“进行时”.

If he hadn't been evicted by his landlord, he wouldn't have been sleeping in the streets.

c 我们可以混合类型2和3

If Tom was a bit more ambitious, he would have found himself a better job years ago.

If you hadn't woken me up in the middle of the night, I wouldn't feel so tired now.

注意

We can also use a Type 1 condition with a Type 3 main clause.

If you know London so well, you shouldn't have got lost.