指代不清(Ambiguous Reference of Pronouns)
　　指代不清主要讲的是代词与被指代的人或物关系不清，或者先后所用的代词不一致。试看下面这一句：

　　Mary was friendly to my sister because she wanted her to be her bridesmaid.
　　玛丽和我姐姐很要好，因为她要她做她的伴娘。

　　读完上面这一句话，读者无法明确地判断两位姑娘中谁将结婚，谁将当伴娘。如果我们在托福写作中把易于引起误解的代词的所指对象加以明确，意思就一目了然了。这个句子可改为：Mary was friendly to my sister because she wanted my sister to be her bridesmaid。

　　例1. And we can also know the society by serving it yourself.
　　剖析：句中人称代词we 和反身代词yourself指代不一致。
　　改为：We can also know society by serving it ourselves.