Final answer:
The subject pronoun in Spanish is 'yo'.
Step-by-step explanation:
The subject pronoun in Spanish is 'yo'. Subject pronouns are used to replace or refer to nouns that are the subject of a sentence. They indicate who or what is performing the action of the verb. Other subject pronouns in Spanish include 'tú' (you, informal singular), 'él' (he), 'ella' (she), 'nosotros' (we), 'vosotros' (you all, informal plural), 'ellos' (they, masculine), and 'ellas' (they, feminine).
Learn more about Subject Pronouns in Spanish