She __________(may) go to the park yesterday .解释句意并说明理由

She might have gone to the park yesterday 她昨天也许去了公园.这是虚拟语气的用法为什么加 have？？may +have done 过去虚拟用法【may的虚拟语气的用法】 在whatever，whichever，whenever，whoever,wherever，however,no matter wh-等引导的让步状语从句中，从句虚拟语气结构为：　　指现在或将来：may +do。　　eg：　　We will finish it on time no matter what may happen.　　不管发生什么事，我们都要按时完成。　　We will find him wherever he may be.　　无论他在哪里，我们都要找到他。　　I will wait for him no matter how late he may come.　　不管他来的多么晚，我都会等他。　　指过去：may +have done 。　　eg：　　You mustn't be proud whatever great progress you may have made.　　不管你取得了多么大的进步，你也不能骄傲。　　We must respect him no matter what mistakes he may have made.　　不管他犯过什么错误，我们必须尊敬他。还有其写法吗？She __________(may) go to the park yesterday .go不变动的可以啊，直接用might。我上面的解释里面有哦亲，may+do 哦