A. Unclear pronoun reference can create confusion. For example, if I say, " I saw your brother and his friend. He didn't know you were going to New York," it is not clear whether the brother or the friend didn't know you were going to New York.
Here's another example. This was taken from the New York Times Headlines on the Web on March 23, 2001.
" Look, the Nasdaq is America's Viagra without it, we just don't feel quite so potent." [Without what? The quotation doesn't make sense.] Actually it is a typo. Here is the correct quotation as it appeared in the column:
" Look, the Nasdaq is America's Viagra--without it, we just don't feel quite so potent."