Respuesta vs. contestación
While both respuesta and contestación translate to answer or response in English and are often used interchangeably, there are subtle differences in connotation, formality, and common usage. Respuesta is the most general and widely used term, while contestación tends to be more formal or used in specific contexts.
Respuesta
A1This is the most common, neutral, and versatile word for answer, response, or reply. It can be used in virtually any context, from a casual conversation to a scientific finding, and is the default choice in most situations.
La profesora no aceptó mi respuesta a la pregunta del examen.
(The teacher did not accept my answer to the exam question.)
Aún estoy esperando una respuesta a mi correo electrónico.
(I am still waiting for a response to my email.)
Su rápida respuesta nos ayudó a resolver el problema de inmediato.
(His quick reply helped us solve the problem immediately.)
La respuesta del público al nuevo producto fue abrumadoramente positiva.
(The public's response to the new product was overwhelmingly positive.)
No siempre hay una respuesta fácil para las preguntas difíciles de la vida.
(There isn't always an easy answer to life's difficult questions.)
La respuesta inmune del paciente fue más fuerte de lo esperado.
(The patient's immune response was stronger than expected.)
Contestación
B2This word also means answer or reply, but it carries a more formal, official, or even legalistic tone. While the verb contestar (to answer) is very common, the noun contestación is used less frequently in everyday speech. It often refers to a formal, written, or official reply to a specific request, complaint, or legal action.
El abogado tiene un plazo de veinte días para presentar la contestación a la demanda.
(The lawyer has a period of twenty days to file the answer to the lawsuit.)
Recibirá una contestación por escrito de nuestro departamento de atención al cliente.
(You will receive a written response from our customer service department.)
Su carta de queja no ha recibido contestación por parte de la empresa.
(Your complaint letter has not received a reply from the company.)
La Embajada emitió una contestación formal a las acusaciones.
(The Embassy issued a formal response to the accusations.)
Su contestación fue muy directa y no dejó lugar a dudas.
(His reply was very direct and left no room for doubt.)
En contestación a su amable carta, le adjunto el catálogo que solicitó.
(In reply to your kind letter, I am enclosing the catalog you requested.)
Summary
In essence, respuesta is the all-purpose word for answer and is appropriate for almost any situation. Contestación is a more formal synonym, best reserved for official, administrative, business, or legal correspondence where a formal reply or response is being discussed. When in doubt, using respuesta is always a safe and natural choice.