Which would I use??
I need to know which one I would use when asking What is your telephone number? in Spanish. Cúal or Qúe?
4 Answers
¿Cuál es tu número de teléfono?
¿Qué es... would be asking for the definition of what your telephone number means.
From what I gathered through reading and some formal training here and there, I decide between both words like this:
Qué (note the accent is on e, not u) - use to inquire about something you don't know, like in your case the phone number - in English mostly 'what?'
Cuál (note the accent is on a, not u) - use if you have to decide between two or more things that are known or seen. say in your case you are looking at two different phone numbers and you want to know which is the office phone number, you would probably say '¿cuál es el número de telefono de la oficina? - in English mostly 'which one?'
Here is another thread on the subject where you should find good information, too. What is the difference between qué and cuál
ps. You might note that the heading in the formal question "title" made it easy for me to find the thread.
¿Cuál es tu número de teléfono?