Ambiguous pronouns
(Sorry if this is a repeat; I have a feeling I've talked about this before, but I can't find any reference to having done so.)
I keep seeing sentences structured something like this:
I placed the pen on the table, then stared at it.
The it is mildly ambiguous; it could refer to either pen or table. In most people's usage, though, most of the time, it would refer to pen, because using a pronoun to refer to the object of a preposition in the preceding clause is often confusing.
If the only noun in recent memory is the object of a preposition, it's sometimes not so bad:
I hovered over the table, staring at it.
But even then, if there's another noun that could reasonably be meant, I tend to resist assuming the object of the preposition is the referent for the pronoun:
I set the pen down. Then I hovered over the table, staring at it.
I'm inclined to read that it as referring to pen.
I vaguely recall that there's a great deal of argument over whether using a pronoun to refer to a preceding object-of-preposition is grammatically valid, but I don't have time to go look that up right now. For now, I'll just note that whether or not it's correct grammar, it can be confusing and awkward, and I generally recommend rephrasing to avoid it.
