"What's the price of this watch?"
Translation:¿Cuál es el precio de este reloj?
Here is a more thorough write-up of the choice between "qué" and "cuál". I would mention that at least in the English-from-Spanish course, you'll see "cuál" (as opposed to "qué") immediately before a noun. You'll also very likely see Spanish-speaking users complaining about this usage in the relevant discussion. My impression is that there is regional variation.
The important case of "¿Qué es esto/eso?" also doesn't clearly fit into the "look it up in a dictionary" guideline for when to use "qué," but I suppose if you expand the set of reference works to include Google Image look-up, it'd still work ;)
EDIT (addendum to first paragraph): The Real Academia Española officially says "cuál" is equivalent to "qué" before a noun, but that this usage is much more common in the Americas than in Spain.
I always equate "cuál" with "which," and then follow this logic:
Of the many prices that this watch could possibly have, WHICH ONE does it have?
In Mexico they often say, "Cuál es su nombre?" I always thought it was a strange turn of phrase until I thought, "There are millions of names in the world; WHICH of those millions is yours?"
Thinking this way helped me understand the usage. Every language has its own unique logic. Try to find it! I hope this helps.
This has been asked numerous times in different discussions. It is also explained by Duolingo under the Tips. When you click on a skill, click Tips for essential info and hints about Spanish. Click them and learn.
Este is masculine, esta is feminine. Esto is more esoteric. Learn more at https://forum.duolingo.com/comment/5388844/When-do-you-use-Esto-esta-este-eso-esa-ese-estos-estas
My line of thinking for using qué over cuál (and i had a very long interal debate before i went with qué and ultimately got it wrong) Cuál is used for choosing from a between a number of outcomes, (like the english which), right? I thought qué was more open ended. So when the question asked how much does the watch cost, there are infinite possibilities because there are so many numbers and coin amounts. It isnt a situation i would think to use Cuál. Do u always use Cuál with numbers or something? If i can just memorize that rule, even tho this doesnt make sense to me, i can just memorize that and move on. If not, please explain! Im so hopelessly confused