so I typed in "which are our birth dates?" and that turned out to be wrong. it figures.
There's a lot of confusion about "Qué" vs "Cuál", because people get taught incorrectlty that qué=what and cuál=which. Here is a better description... http://spanish.about.com/cs/grammar/a/que_vs_cual.htm
This particular example falls under the rule "Cuál usually is used before es and other forms of ser when not seeking a definition".
The main diference is that 'cuál' is used to get information about a closed group, the dates of bith can only be dates. If the group is open then we use 'qué', but this rule is not a law.
I can only think of one reason which makes sense: you are asking a friend if they remember both yours, and another friend's birthday.
Or if you're trying to write a list of birthdays for an office or something, and being inclusive in your statement. On second thought it is kind of unusual in english.
You can use "qué" but you must change the order "¿Qué fechas de nacimiento son las nuestras?" Both sentences are equivalents, but the second is not usual.
This falls under "weird things no one says". Unless you have a twin and you forget when you were born I guess. Anyway, I was hoping to get a little further clarification on "Cuáles" vs. "Que" because I think I know what you mean by open vs. closed, but am not 100%. Maybe an example of each would be helpful to be certain.
Wouldn't the translation be "when are our birthdays?" "What are our dates of birth" or "what are our birthdays" would require an explanation that that is the day we begin life... no?
"fecha de nacimiento" is always "date of birth" (the thing you fill in on forms, etc), whereas "birthday" is "cumpleaños".
When referring to a "date of birth" you would always use "what" (not "when") because it is a piece of data, just like name, weight, height, eye-color, etc.
I'm always torn about whether translations should be equivalent or literal. You're right, in that the real question should be "When are our birth dates?" not "What," but then would you say that in spanish they're asking "when" or that they're actually asking "what" or even "which" but we would use a different word in english (when). Then if you're doing an equivalent translation, where do you draw the line for "interpreting"? Would you translate it as "When are our birthdays?" because that's what we would say in english (putting aside the absurdity of the question), or is that going to far, since the word you'd translate as "birthday" is actually "cumpleaño"??
'Cual' is used when the options are closed, you have to choose. 'Que' is for an open question. For asking about days is common to use cuales, because you have to choose one of a group.
I think that is because "dates" is plural and "birthday" is singular. You could ask "What are the dates of our birthdays" or "What is the date of our birthday", but in this case, both are plural
A birthday is celebrated every year, and the Spanish word is "cumpleaños". This sentence is about "date of birth", which is the singular date in the past on which a person was born.
I typed "birthdate" in lesson 9 and got it wrong. I typed "birth date" here and also got it wrong.
No, it's because on some questions it only accepts "birthdate" and on others it only accepts "birth date."