Pregunta vs. cuestión
While both pregunta and cuestión can be translated as "question" in English, they serve distinct purposes in Spanish. Generally, pregunta refers to an interrogation seeking information, while cuestión refers to a matter, issue, or topic.
Pregunta
A1This word refers to a specific interrogative sentence or a request for information. You use pregunta when you are asking something and expecting a verbal or written answer.
¿Puedo hacerte una pregunta rápida?
(Can I ask you a quick question?)
La pregunta número cinco del examen es muy difícil.
(Question number five on the exam is very difficult.)
El testigo respondió a cada pregunta honestamente.
(The witness answered every question honestly.)
Si tienes alguna pregunta, levanta la mano.
(If you have a question, raise your hand.)
Su pregunta me tomó por sorpresa.
(His question took me by surprise.)
Cuestión
B1This word refers to a subject, an affair, a matter, or a dilemma relative to a situation. It describes the central point or theme of a discussion rather than the grammatical act of asking for an answer.
No es una cuestión de dinero, sino de principios.
(It is not a question of money, but of principles.)
Es solo cuestión de tiempo antes de que lleguen.
(It is only a matter of time before they arrive.)
Esa es una cuestión que debemos discutir en privado.
(That is an issue we must discuss in private.)
La seguridad es una cuestión de gran importancia.
(Safety is a matter of great importance.)
La cuestión es que no tenemos suficiente comida.
(The issue is that we do not have enough food.)
Summary
In short, use pregunta when you want an answer to an inquiry. Use cuestión when you are talking about an issue, a topic, or a matter of importance.