Correcting Unclear Pronouns
A third-person pronoun (he, she, it, they, him, her, its, their) needs to refer clearly to its antecedent. An unclear antecedent creates confusion and sometimes humor.
Confusing: The red-breasted robin returned to the nest while Marsha watched, and she coughed up a worm to feed her babies.
(She seems to refer to Marsha, the closest singular feminine noun form.)
Clear: While Marsha watched, the red-breasted robin returned to her nest, and she coughed up a worm to feed her babies.
(Now, she clearly refers to the red-breasted robin.)