by even if ，even though 引导的虚拟语气时态
与过去相反的假设 从句：had done 主句：would、could，might，should have done
与现在和将来相反 从句 一般过去式 主句would、could，might，should do
用在asif/as though，或evenif/even though引导的从句中:
如果从句中表示的动作发生在过去，则谓语动词用had＋过去分词形式如果指的时现在的状况，则用过去式 (be用were)指将来则用would(should，could)+动词原形.这里只看从句动作发生的时间，与主句的时态没有关系.如：
He went out even though it was raining.
    He is the best student even though he has the least time to study.
    Even though I feet sorry for father， l am secretly pleased that he has the time to play with me.
Even though he hurted her， she still loves him.
    
even though引导的虚拟语气从句时态
他不是虚拟语气，如果说过去的事情就用过去时Even though he didn't know it，I will do it by myself.即使他不知道我也要做
如果说将来的事情就将来时