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If you'd have performed the operation yesterday like you were supposed to...
如果你按计划昨天就给我做手术
...I'd be sucking carrots through a straw in my arm.
我现在就能用吸管喝胡萝卜汁了。
关于if引导的虚拟语气
1. 虚拟条件句时态的基本特点：虚拟条件句可以表示过去，现在和将来的情况，时态的基本特点是时态往后推移。
1).对现在的虚拟;if条件从句用一般过去时（be用were），主句用should（would）等 +动词原形。如;高三册unit 8 8单元p69：If I hadn’t piles of homework to do , I would relax. 如果我没有成堆的作业要做，我就会轻松。（事实上我有许多作业要做，不能放松）注意：在虚拟语气的从句中，动词'be'的过去时态一律用"were"，不用was，即在从句中be用were代替。如： If I were you, I would go there. 如果我是你，我就会去那儿。
2). 对过去的虚拟:if条件从句用过去完成时(had done),主句用should（would）等+ have done.如：高三册unit 8 p70：If it hadn’t had a flat tyre , I should / would have lent my car to George that morning .如果车没有一个瘪轮胎的话，我那天上午会把车借给乔治的。（事实上车有一个瘪轮胎，我那天上午没有把车借给乔治）
3). 表示对将来不大可能发生的事情的虚拟:if条件从句用一般过去时（be用were）/were+ to do /should+ 动词原形,主句用should/would等 + 动词原形. 如：If you succeeded/ should succeed / were to succeed, everything would be OK. 如果你将来成功了，一切都会好的.
2. 错综条件句：主句与从句的动作发生在不同的时间，主句从句谓语动词的虚拟语气形式因时间不同而不同，这种条件句叫做混合条件句。主要的考点是if条件从句是对过去的虚拟用had done，主句是对现在的虚拟用should/would等 + 动词原形。
如：高三册unit 8 p70：If I had been brought in Britain as my cousin was, I would speak English as she does . （从句与过去事实相反，主句与现在事实相反。）
If you had asked him yesterday, you would know what to do now. 如果你昨天问过他，今天就知道做什么了。
If it had rained last night（过去）, it would be very cold today （现在）.如果昨晚下过雨，今天就会很冷了。
3. 虚拟条件句中的省略和倒装：虚拟条件句的if从句部分含有were, should, 或had时, 可省略if，然后把were, should或had 移至从句的句首，进行倒装。主句部分保持不变。
如：高三册unit 8 p70：If I had been brought in Britain as my cousin was，…=Had I been brought in Britain as my cousin was ，…
高三册8单元p70：If it hadn’t had a flat tyre , I would have lent my car to George that morning = Had it not had a flat tyre, I would have lent my car to George that morning
Were they here now( =If they were here now ), they could help us.如果他们现在在的话，就能帮助我们了。
Should it rain（=If it should rain）, the crops would be saved., the crops would be saved.假如下雨，庄稼就有救了。
