Use this checklist as a list of reminders while you are editing your paper.
6. Incorrect pronoun case
Determine whether the pronoun is being used as a subject, or an object, or a possessive in the sentence, and select the pronoun form to match.
Castro's communist principles inevitably led to an ideological conflict between he and President Kennedy.
Castro's communist principles inevitably led to an ideological conflict between him and President Kennedy.
Because strict constructionists recommend fidelity to the Constitution as written, no one objects more than them to judicial reinterpretation.