I would和I had都是I'd，该怎么区分？

英语自学网

　　在英文中，有很多常用的小词，比如 I'd ，但到底是I would还是I had，学习英文不能马虎，今天一次教给你!
        　　I would
        　　I would+动词原形
        　　I'd see
        　　I'd walk
        　　I'd study
        　　If I were you, I'd rather go.
        　　如果我是你，我就去
        　　If I were rich,I'd travel around the world.
        　　如果我有钱，我就去环游世界
        　　I had
        　　I had+过去分词构成过去完成时
        　　I'd seen
        　　I'd walked
        　　I'd studied
        　　He'd already left when we arrived.
        　　当我们到的时候，他已经走了
        　　I felt absolutely certain that I'd seen her before.
        　　我完全确信自己以前曾见过她