Cos'è (or Che cos'è) vs. Qual è
So even after almost two years of learning and strengthening, this morning I find myself having an "aha!" moment. Forgive me if this seems obvious to you...
On Duolingo sentences, we are initially taught that cosa means "what", and Che cos'è means "what is (it)".
Pretty soon afterward, we dropped the "che" in front of "cosa", and we accepted this fact, much in the same way that we learned to drop "io" in front of "sono", or "noi" in front of "siamo". It's there, but it doesn't have to be.
In fact, "che" more often means "that", as in the Present Subjunctive sentence, "Penso che lei è bella." (I think that she is beautiful.)
Then we eventually reach a unit-- I forget which one-- and we are suddenly presented with a sentence like, "Qual è il tuo nome?" or "Qual è il suo lavoro", and we say to ourselves, 'Duo just taught us that Quale means "which"! So does that sentence not say, "Which is your name?" or "Which is his work?" ? What is going on here?'
So this was my "aha" moment today: When is it the right time to choose Cos'è , and when is it the right time to choose Qual è ?
Reading through the comments of a certain sentence, someone posted that you should use Cos'è when you want to know the definition of something, or if there could be many correct answers.
- What is it? (I don't know what it is; do you know what it is?)
- What is it that you see? (I see a red car-- I also see plenty of other things, but that is a red car.)
You should use Qual è when you are asking for personal information or about a personal fact.
- What is your age? (I don't know, but I know for certain that you can tell me.)
I hope that this insight is correct, because it can now start to make sense to me.
You can still learn things by reading through comments on sentences that you believed that you already knew, so I encourage people to check out what other people are asking about. You might be able to help someone who has the same problem that you once did, and you might just discover something new, to help yourself, as well.
Quale is an adjective, so it goes with a noun, even if it is implicit... example: you are talking with your friend about books, then she ask you: "Qual è il tuo preferito?" In this question there is not the word "libro", but you know that "qual = quale" is referred to "libro"... in your example quale goes with "età". As Thenoblesunfish said, ""Quale : asking about which member of an implied set""..this looks a very good explanation too.
Cosa is not an adjective, so it doesn't go with a noun...It's used when the answer to your questions can be everything "What is it? = Cos'è?" It can be everything..if I'm asking you, it means i have no idea...
Another example: you telephone to someone: "What are you doing? = Cosa stai facendo? (you have no idea: he could sleep, or watching tv, or washing his car)...He answer: I'm doing the math exercise... at this point, you know that he had to do three exercises, so you ask "Quale?" (esercizio is implicit) = "Which one?"... you can also ask "Quale esercizio stai facendo?"
I think, but i'm not so sure, that in general, when you in English can use "which", in Italian you use "quale"...when you must use "what", in Italian it's "cosa"...
I tried my best with my limited English...I hope to not confuse you even more..
Short answer: there are exceptions.
Long answer: there are exceptions. My opinion/experience is that languages are designed to be adaptive and elastic rather than purely mechanical systems. This feature is supposed to take into account and to better encompass historical heritage, social relationships and idiomatic pushes.
Rules are a cornerstone while you learning something new, but that doesn't imply always immanent application. In some occasions you have to memorize the most widespread patterns/formulas.
So, would you agree with this?
(Che) cosa : asking about the nature of something
Quale : asking about which member of an implied set.
This indeed confusing to anglophones because (at least informally) we tend to use
what for the first case and some of the second.