They is not a second-person pronoun. It’s a third-person pronoun that can be plural or singular. Plural “they” refers to two or more people or objects (e.g., “The cats are sleeping because they are tired”). Singular “they” refers to one nonbinary or hypothetical person whose gender is irrelevant or unknown (e.g., “I don’t know who painted this mural, but they are so talented”).
QuillBot’s free Grammar Checker can help you use pronouns like “they” correctly.