vs
QUICK ANSWER
"Cuál es el problema" is a form of "cuál es el problema", a phrase which is often translated as "what's the problem". "No sé qué" is a phrase which is often translated as "I don't know what". Learn more about the difference between "cuál es el problema" and "no sé qué" below.
cuál es el problema()
A phrase is a group of words commonly used together (e.g., once upon a time).
a. what's the problem
¿Puedo hablar contigo? - Sí, ¿cuál es el problema, Roberto?May I speak with you? - Yes, what's the problem, Roberto?
a. what the problem is
Dime cuál es el problema y trataré de solucionarlo.Tell me what the problem is and I'll try to solve it.
no sé qué, el no sé qué()
A phrase is a group of words commonly used together (e.g., once upon a time).
a. I don't know what
No sé qué hacer para aprobar el examen de inglés. ¡No entiendo nada!I don't know what to do to pass the English test. I don't understand a thing!
A masculine noun is used with masculine articles and adjectives (e.g., el hombre guapo, el sol amarillo).
a. a certain something
Le falta un no sé qué a la pintura. Algo que la haga memorable.A certain something's missing from the painting. Something that makes it memorable.
b. no direct translation
The following examples show ways to translate this word or phrase without using a direct equivalent.
Tatiana tiene un no sé qué que la hace una mujer muy interesante.Tatiana has a je ne sais quoi that makes her a very interesting woman.
John tiene un no sé qué que hace a mi corazón latir más rápido.There's something about John that makes my heart beat faster.
