Is this pronoun case correct?

Perdo Martinez signed a baseball for Chad that he had used in a game.

The problem with that sentence is you have a adjective clause that isn't in the right place.

I would rearrange to start the sentence with For Chad, Pedro Martinez...etc.

Actually, the problem with the sentence is the incorrect use of pronoun case. In this case, the pronoun "he" should be changed to "Pedro Martinez" to maintain clarity and proper pronoun case agreement.

To determine the correct pronoun case, we need to analyze the antecedent of the pronoun. In the sentence, "Pedro Martinez" is the antecedent of the pronoun "he". However, since "Pedro Martinez" is the subject of the clause "signed a baseball for Chad," we need to use the nominative case pronoun, which is "he".

Therefore, the corrected sentence would be: "Pedro Martinez signed a baseball for Chad that he had used in a game."

To check the correctness of pronoun case, it's important to identify the antecedent and the role it plays in the sentence. This ensures that the pronoun agrees in both number and case with its antecedent.