Final answer:
The subject pronouns tú, usted, and ustedes are used to address different people or groups of people in Spanish.
Step-by-step explanation:
To talk to your best friend, you would use the subject pronoun tú. For your doctor, you would use usted. When talking to your parents, you would use ustedes. The subject pronoun for your friends and two classmates would be ustedes. Your grandmother would be addressed using usted. A police officer would be addressed using usted. Your elderly neighbor would also be addressed using usted. For one classmate, you would use tú. Your younger neighbor would be addressed using tú. Neighbors your age would be addressed using ustedes. Your bus driver would be addressed using usted. Lastly, a group of teachers would be addressed using ustedes.
Learn more about Spanish subject pronouns