結構，造句，背過——
（一）、（完全結構）主句與從句都是相反的表意：if / even if (even though):如果/即使
1、與過去虛擬：
【"從句If +had done, 主句+ could/should/would/might've done"】能/該/會/可以
If I hadn't got up so late, I could've got there earlier.
If I had got up earlier, I could've caught the train.
If I hadn't fixed my car, I should've taken part in the conference call.
If you had passed the exam, I would've bought a car for you.
If I had got there earlier, that kid might've been rescued/saved.
If I had known he was this kind of person, I wouldn't have helped him.
If you had told me earlier, I wouldn't have been so angry with him.
2、與現在虛擬：
【從句If + did/were, 主句could/shoud/would/might do】
If I had money, I might buy a car.
If I had a brother or sister, I could ask him/her for help.
If I were you, I wouldn't do that.
Even if i knew, i wouldn't tell you.
3、與將來虛擬：
【從句If + did/were to/should do, 主句could/should/would/might do】
If it rained tomorrow, we would call off the class.
If it were to rain tomorrow, we would call off the class.
If it should rain tomorrow, we would call off the class.
Even if i should go/ i went/ i were to go, i wouldn't take you with me.
（二）、（簡化版）只有主句表意相反=與結果相反
【從句正常陳述，主句虛擬（同上），用otherwise/or/but for/without連接】
1、與過去結果相反：
I got up so late, otherwise/or, I could've got there earlier.
I got up so late, otherwise/or, I could've caught the train.
The traffic was heavy, otherwise, I could've taken part in the conference call.
I didn't know he was this kind of person, otherwise, I wouldn't have helped him.
Without/but for your support, I couldn't have finished my homework.
Without/but for your support and help, this book couldn't have been possible.
2、與現在結果相反
I don't have money, otherwise, I might buy a car.
I am not you, otherwise I wouldn't do that.
I don't have a brother, or, I could ask him for help.
Without/but for sunlight, there would be no life on the planet.
Without water, we couldn't live.
3、與將來結果相反
It might not rain tomorrow, or, we would call off the class.
（三）、（簡化版）與從句相反=與事實相反
【從句虛擬，將來時稍有變化】
1、wish / How I wish: 我多希望……
（與現在事實相反）
How I wish you came.
I wish I had a lot of money.
I wish I could have more time to be with them. ----can的過去式
I wish i didn't need to study so hard everyday.
How I wish it were not raining.
How I wish i were as strong as you.
How I wish I were you.
I wish everyday were my birthday.
（與過去事實相反）
I wish I hadn't eaten so much watermelon.
I wish I hadn't seen him.
I wish I hadn't heard this news.
I wish I hadn't been so angry with him.
（將來事實相反）
I wish it could/would rain tomorrow.
I wish i could grow up faster.
2、If only……：要是……就好了--------------------->>意思、用法=I wish
（與現在相反）
If only i knew he was this kind of person.
If only i had a lot of money.
If only it were not raining.
If only i were you.
If only i were as strong as you.
（過去相反）
If only you had come yesterday.
If only i had taken your advice.
If only i had studied english hard.
（將來相反）
If only he could come tomorrow.
3、as if (as though) : 好像（此處是虛擬用法，不虛擬就正常時態）
（現在相反）
She likes the baby as if the baby were hers.
He looks as if he were drunk.
（過去相反）
They talked as if they had been friends for years.
He speaks english so fluently as if he had been to the US.
（將來相反）
He studies english so hard as if he would go to the US.
4、would rather: 寧願……
（現在相反）
I'd rather you gave me money now.
I'd rather you were not my friend.
（過去相反）
I'd rather you had left.
I'd rather you hadn't told me this thing.
（將來相反）=【現在相反用法: did/were】
I'd rather you didn't come tomorrow.
I'd rather it didn't rain tomorrow.
I'd rather you came tomorrow.