Yo estudio español.
English: I study Spanish.
Subject pronouns in Spanish are words like 'yo', 'tú', 'él', 'ella', etc., that show who is doing the action in a sentence.
Use subject pronouns in Spanish to say who is doing something. Sometimes, the pronoun is not needed because the verb form already shows the subject. Use them for emphasis or clarity, or when you want to change the subject.
Yo estudio español.
English: I study Spanish.
Tú eres mi amigo.
English: You are my friend.
Él vive en Madrid.
English: He lives in Madrid.
Nosotros comemos pizza.
English: We eat pizza.
Ellas bailan muy bien.
English: They (feminine) dance very well.