Wereitfortheirhelp,wewouldnothaveovercomethedifficulties.请问这句话有问题吗？包括时态和句意。这是本教科书上的题目。急！！！我知道该题是虚拟语气，主句用的是现在完成时，从句怎么用一

Question

Were it for their help,we would not have overcome the difficulties.
请问这句话有问题吗？包括时态和句意。这是本教科书上的题目。
急！！！
我知道该题是虚拟语气，主句用的是现在完成时，从句怎么用一般过去时？还有从句中是不是缺少了一个not？
原题是Were it for their help ,we (not overcome)_______the difficulties.

Answer 1

it 后加not
原句：If it were not for their help,we would not have overcome the difficulties.
if 从句是对现在事实的虚拟，主句是对过去事实的虚拟。该句是典型的错综时间的虚拟语气。