yes

"Sí" is the fundamental word used to express agreement, affirmation, or consent in Spanish. It functions as the direct equivalent of "yes" and serves as a versatile tool for answering polar questions, confirming statements, or signaling that you are following along in a conversation. While "sí" is universal, remember that in Spanish, the accent mark (tilde) is crucial to distinguish it from "si" (without the accent), which means "if." In casual settings, it is often repeated for emphasis, such as "sí, sí" to show you are listening or to agree enthusiastically.
In conversation
Agreeing to plans
¿Quieres ir al cine esta noche?
Do you want to go to the cinema tonight?
¡Sí, claro! Me encantaría.
Yes, of course! I would love to.
Using 'claro' alongside 'sí' makes your agreement sound more natural and enthusiastic.
Confirming a fact
¿Has terminado el informe?
Have you finished the report?
Sí, ya está en su correo.
Yes, it is already in your email.
In formal contexts, a simple 'sí' followed by a complete sentence is polite and professional.
Examples
Sí, por favor.
Yes, please.
¿Puedes ayudarme? Sí, puedo.
Can you help me? Yes, I can.
Si me dices que sí, iremos juntos.
If you tell me yes, we will go together.