Translation:Miss, what is your telephone number?
The way that I was taught the distinction between "qué" and cuál" is that "qué" asks for a simple definition, an explanation, or specific information. So "¿Qué es su número de teléfono?" would require an answer like "My phone number is a combination of seven digits preceded by a three-digit area code." Whereas "¿Cuál es su número de teléfono?" is asking, literally, which phone number is yours, but, in English, we say "What is your phone number."
A fellow DL user, Majklo_Blic, explains this so well. I'll quote him. "In general, Qué is used when asking for a definition, or when there are few or no restrictions on what the answer might be. (¿Qué onda? What's up?)
Use cuál when there's a restricted pool of answers to choose from. (¿Cuál es tu número? What's your number?)
Cuál can also mean "which." (¿Cuáles de los gatos son tuyos? Which of the cats are yours?)
Throw Majklo_Blic a follow :)
"Su" is the third person possessive pronoun. "Tu" is an informal "you" and therefore second person. "Usted" is the formal "you" and therefore third person. When showing possession by a third person noun/pronoun, you use the third person version, thus "su." Thus talking to someone you respect, you would say "su numero," whereas talking to a casual acquaintance, you might say "tu numero." In late modern English, there is only one form of "you" for both formality and number, so we just say "your" in either case. In an older form of english, "su numero" would be "your number" and "tu numero" would be "thy number," but erring on the side of formality became so prevalent that the informal version has been dropped from common usage entirely.
First, I would like to say that the second (singular) person of the speech, "You", can be translated into "other expressions", other than "Tú".
These expressions are:
If for "Tú" the possessive pronoun is "tu", these "other expressions" of Second Person use "borrowed" the possessive pronoun "su", of third person (the same is true for conjugation of verbs).
SECOND PERSON OF THE FORMAL SINGULAR
You, your =
Hope this helps.
Unfortunately the translation of "what" isn't as simple as a one to one translation. "Cual" sometimes means 'what' in sentences where "qué" is not appropriate to use. As has been said elsewhere if there are only a limited number of options to choose from (even if there are thousands of options, like with phone numbers) then 'cual' is likely the correct option and "qué" would be incorrect.
Duo has been terribly inconsistent with the English translation for señora & señorita. There was one place I used "Miss" for "señorita" & was corrected with "Lady". This time I use "Lady" & was corrected with "Miss". Please, please!!! I know exactly what each of these words means!!!! It is so frustrating!
Europe used to be pretty patriarchic, so it mattered a lot to a woman's status whether she was "taken" by a man or still available. A lot of the continent is rolling back on it, though, and at least some countries have abolished the addressing for unmarried women.
"Ms" is an abbreviation and should only be used when you also mention that lady's (last) name.
Su is the general 3rd-person grammar possessive adjective. In this special case, that means it's going with the formal "you" form, usted. Since you're addressing the lady with the formal señorita, you need to continue with usted grammar and hence use su.
Tu is the possessive form of the informal tú.
- Señor, ¿usted me dice su número de teléfono? - formal
- María, ¿tú me dices tu número de teléfono? - informal
Su is used when you're talking about the possession of él, ella, ustead, ellos, ellas, or ustedes. Since you're addressing the person in this sentence as señorita, she's going to be an usted, so su is used here.
Tu is used for talking about the possession of tú, which are usually people you'd address with their first name.
That general rule only works if you have any other verb than ser after the question word. For example:
- ¿Qué quieres comprar? - What do you want to buy?
- ¿Cuál quieres comprar? - Which one do you want to buy?
But when the verb is ser, this application doesn't work anymore. In that situation qué will ask for a definition, and cuál for specific information instead:
- ¿Qué es un número? - What is a number?
- ¿Cuál es tu número? - What is your number?
Also when asking about people, you pretty much always use quién.
When speaking about a woman in English, calling her "a lady" is complementary, whereas addressing her as "lady" is generally considered abrupt if not outright rude.
Acceptable: The lady has a very beautiful house. She is a smart lady. What was that lady's name?
Rude: Lady, I have another napkin? I disagree, Lady.
We would use miss when addressing a person and lady when speaking about the person to someone else.