But if you were to look deeper and think further

题目

But if you were to look deeper and think further
But if you were to look deeper and think further,这句话和But if you look deeper and think further有什么区别?
加上were是因为虚拟语气吗?

答案

加上were to实际上是be to do结构,这个结构可以表示将来,表打算做什么事情.这里是假设的过去的情况,但是be to do后面的动作相对过去的那时刻而言还是将来的情况,所以用be to do这个表将来的情况.但是事实上呢,这个假设情况都已经是过去的事情了,所以be to do结构还是要用过去时态的.
不知道讲清楚没有,如有不妥之处敬请各位指正.