英语条件句：什么是第一、第二、第三和零条件句(2)

主句是祈使句也常见：
Come play with me – if you dare!
来和我玩吧——如果你敢的话！
If mixture won’t fully blend, add a little more water.
如果（面粉等）没有混合均匀，再加一点水。
02第二条件句
属于非真实条件句，即虚拟条件句，用于表示与现在事实相反或将来成为现实的可能性很小。
从句（if）用过去式，表示想象的事情（条件），主句用would 动词原形，表示推测的想象结果。
If shaming reduced obesity, there would be no fat people.
如果羞辱胖子能减少肥胖，就不会有胖子了。
If mother were/was here, she would be able to tell us the answer.
如果母亲在这儿，她就能告诉我们答案了。
（注意虚拟语气中were往往代替was）
If she were to fail his driving test tomorrow, she would have to take it again.
如果她明天驾驶考试不及格，她就得再考一次。
03第三条件句
也是虚拟条件句，用于表示与过去事实相反的情况。
从句（if）用过去完成时，主句用 would/should have 过去分词形式
If they had left earlier, they would have been here already.
如果他们早点走，他们早就到了。
It would have been better if you had practiced a bit more before your presentation.
如果你在陈述前多练习一点就更好了。
04零条件句
用于表示只要满足了某个条件，总会出现某种现象或导致某种结果（通常被认为是绝对会发生的真理，科学事实等）。
If by some chance you don"t practice yoga, perhaps this may inspire you to try it.