Pronouns replace nouns, and the nouns they replace are called antecedents. Readers must be able to logically connect antecedents to their pronoun. And, pronouns need to agree with their antecedent in number, gender, and person. Most legal writers don’t have problems making pronouns agree with their antecedents in gender. Number and person can be a little trickier. If your sentence is confusing, there may be a problem with the antecedent and there may be a problem with the pronoun – so I’ll talk about each. [excerpt]
Tenielle Fordyce-Ruff, Pronoun Problems, Part 1, 55(3) Advocate 42 (2012).