If I had money, I could buy the car.
If I knew her number, I would call her
If I were rich, I might go there
2、过去完成时（if + 主语 + had + 过去分词......could/would/might/should + have + 过去分词。）If I had studied hard, I could have passed the test.
If I had known her number, I would have called her.
If she had helped me, I should have finished it.
If I had got up early, I could have caught the bus.
3、错综虚拟语气（if + 主语 + had + 过去分词..could/would/might/should + 动词原型 + now/today/like this.）说明：当过去的假设对现在还产生影响时，用错综虚拟语气，
If driver had been careful, those people could be alive now.
If I had married her, I could be living happily now.
4、将来时（if + 主语 + should +动词原型 ... will/can/may/shall/could/would/should/might+动词原型; if + 主语 + were to + 动词原型...could/would/should/might+动词原型）if you go, I will go too.
机会50%左右；if you should go, I will go.
机会很小；if you were to go, I would go.
可能性为0；if the sun were to rise in the west, I could marry you.
If driver had been careful, those people could be alive now.
I wish I were a poat. 我要是诗人就好了。
I wish I knew the answer. 我要是知道答案就好了。
2、过去完成时 （I wish ... had + 过去分词）I wish I had taken you advice.我当时接受你的建议就好了。
I wish I had finished the work.我当时完成那项工作就好了。
I wish引导的虚拟语气只有过去时和过去完成时态。例：
He talks as if he were a star. 他说话的方式像个明星一样。
She talks as if she knew everything. 她说话就像什么都知道一样。
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she acts as if she had been sick. 她表现得像生病了一样。
she talks as if she had seen him. 她说话就像见过他一样。
but for your help, we couldn't have finished the task on time.
= without your help, we couldn't have finished the task on time.
= if it had not been for your help, we couldn't have finished the task on time.
if only 用于表达强烈的愿望或遗憾，特别是在某些情况没有发生或无法实现时。
If only he knew how much I love him. （要是他知道我有多爱他就好了。）
If only I were richer, I could buy that expensive car. （要是我更富有，我就能买那辆昂贵的汽车了。）
If only I had studied harder last year, I would have passed the exam. （去年我要是学习再努力点，我就会通过考试了。）
would rather 宁愿 （动词过去式）主要表达的是对现在或将来的愿望，而不是对过去的假设。
I would rather you went to the party tonight. (我宁愿你今晚去参加聚会。)
We would rather you stayed here with us. (我们宁愿你留在这里和我们一起。)
insist （should+ 动词原型） 表示对某种情况或行为的强烈要求或主张，而这种情况或行为可能并未发生或并不符合现实。He insisted that she (should) go to the doctor. （他坚持要求她去看医生。）
They insisted that we (should) attend the meeting. （他们坚持要求我们参加会议。）
advise、sugest （引导词用过去式+that +主语 + should+ 动词原型） 用于表达一种g建议或假设，而不是强制性的要求,通常可以省略shouldHe advised that I (should) study harder. （他建议我应该更努力学习。）
otherwise 否则 or 一坚持:insist 二命令:order/command 三建议:advise/suggest/recommend 四要求:demand/require/request/ask