Final answer:
The pronoun 'he' in the sentence is vague because it could refer to either Steve or Zach. The sentence does not adhere to the clarity required for proper pronoun reference, causing confusion on who exactly felt better.
Step-by-step explanation:
The student asks if the sentence 'After Steve talked with Zach about the research project, he felt better about collaborating on it.' contains a vague pronoun reference. In this case, the pronoun 'he' could refer to either Steve or Zach, making it unclear who felt better about the collaboration. According to the guidance provided in Section 20.6 on clear use of pronouns, the pronoun reference in this sentence is vague and does not effectively meet conventions that demand clarity.
Problems with pronoun reference arise when pronouns like 'this', 'that', 'which', or 'it' ambiguously refer to someone or something previously mentioned, causing confusion about what or whom the pronoun refers to. The intent is to maintain pronoun-antecedent agreement in a way that is rhetorically effective and adheres to conventional expectations. To improve the sentence, one could rewrite it to clearly indicate which person is feeling better: either 'After Steve talked with Zach about the research project, Steve felt better about collaborating on it.' or 'After Steve talked with Zach about the research project, Zach felt better about collaborating on it.'