maybe if I stdied science,and not literature four years ago

Maybe if I had stdied science,not literature four years ago I would be able to give more help。虚拟语气中if引导的从句所描述的事情如果是与过去的事实相反,用过去完成时,所以studied前面要加上had。这句话的主句部分（即后半部分）所描述的事情与现在的情况相反,要用would+动词原形,所以这里不用改动。这句话的主句是对现在的虚拟,从句却是对过去的虚拟,这叫错综条件句。 再问： 如果没有交通堵塞，我就能早点到公司了。if___ ___ ___no traffic jams。I would have got to the company earlier。 再答： there had been