pretty 在这里完全等于 very 的意思, 但是你在这里就不能用 very 来代替 pretty. 或是你可以把 pretty 改成 pretty much , 就成了 I can pretty much understand what you are talking about.   这种用法在日常生活中十分常见, 例如他们会说, We are pretty much the same, 就是我们非常相像的意思.