Final answer:
The subject pronoun used to address a child in Spanish is 'tú'
Step-by-step explanation:
The subject pronoun that you would use to address a child in Spanish is tú. It is the informal pronoun used to address someone who you are familiar with, such as a child or a friend. For example, instead of saying él eres inocente (he is innocent) you would say tú eres inocente (you are innocent).
Learn more about Subject pronouns in Spanish