Avoid vague pronouns
Pronouns replace or refer to a specific noun. Make sure that your pronouns aren't vague or ambiguous.
Examples:
- When the truck stopped next to the car, it was slightly further ahead than the other vehicle (does "it" refer to the truck or the car?)
- The dog chased the cat until it hid under the couch (does "it" refer to the dog or the cat?)
- My birthday is next week, which is exciting (what is exciting, your birthday or that it is next week?).
For more information, please see Vague Pronouns (YouTube video).