请问second conditional句型

题目

请问second conditional句型
条件从句为什么要用过去式?

答案

second conditional is a structure used to talk about an "unreal" or "unlikely" situation.
Structure:if + past tense,would(not)
eg:if my shares went up 500%,I'd tell them instantly.(But it's unlikely it will go up 500%)
就是规定的过去式 没原因.可能是因为假设的事情不可能发生吧～