Question

maybe if I stdied science,and not literature four years ago I would be able to give more help.单句

maybe if I stdied science,and not literature four years ago I would be able to give more help.单句改错

Answer 1

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。

追问

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.

追答

there had been

Answer 2

Maybe if I studied science,and not literature four years ago, I would [have been] able to give more help.

Answer 3

and-->but.
be-->have been
studied 拼写有误
Maybe if I studied science but not literature four years ago, I would have been able to give more help