When one is writing, one must pay attention to pronoun use, especially when the pronoun can be unclear. For example, this morning a jumping spider was found in the van.
Fiona: If he jumps on Jason, I'm going to kill him!
Ian (in his high-pitched Fiona voice): Ack! Get out from under my spider, you bad baby! (pretends to smack a baby)
See? Clear pronouns are very important.