Que and Qué
In an article on the use of the subjunctive in Spanish, I came across the following examples of wishing someone something, or that something may happen:
¡Qué tengas un buen día!, ¡Qué lo pases bien!, ¡Qué aproveche!, ¡Qué te vayas!
Am I correct in believing that there should NOT be an accent on the 'Que' word? (Because 'que' here means 'that' not 'what?'. E.g. '[I hope] that you have a good day!'
Cheers, Alanka
5 Answers
Being the worst student on the planet and disregarding the rules a good part of the time, My lovely wife, a native speaker reminds me of "Que and Qué" in this way:
She says it is simple--an interrogation or a REAL exclamation ( surprise-amazement- anger) it has a tilde.otherwise no.
Example:
Que tengas un buen dia, a short version of "deseo que tengas un buen dia" skips the deseo and you see that it is not a true exclamation, and the que works only as a conjunction to link the wish to the rest of the phrase.
Also que uses a tilde when it substutes the item in question, example:
No sé qué quieres.
Otra:
Dime con qué limpiaste el piso.
Otra:
No tiene qué comer
You're right, well observed. When you say ¡Que tengas un buen día!, you're indeed "leaving out" something like 'Espero' or 'Deseo' at the beginning, so 'que' is really what I like to call a 'sticky word' , that pastes two clauses together, like in 'el dinero que te presté'.
So, if you know your grammar well enough, this rule is perfect for you: 'relative pronoun = que, any other function = qué) If not, keep reading. 
'Qué' (to the best of my knowledge) only wears an accent in interrogative sentences "¿Qué es eso?" & exclamations of the type: "¡Ay, qué calor!" & (I think!) in sentences in which in English you'd stress the 'what' and wouldn't ever use 'that' instead, as if you're making it an independant reference. For example: "No sé qué estaba pensando." - "I don't know what I was thinking."
I don't think it has an accent, but let's wait for the Spanish natives to answer.
I asked my Spanish linguïstics & grammar teacher (at a Dutch university) about this issue and he gave me a 1 sentence answer. Apparently it's a lot easier than we'd all been thinking! :D
When 'que' is used as a relative pronoun, it does not wear an accent; in ALL other cases it does.
(see my earlier answer, when I referred to relative pronouns as 'sticky words' X) )
You may find this article helpful: Relative pronouns in Spanish (wiki)
So to answer OP's question: You're right, because those 'que's' are secretly still relative pronouns.
En este caso las frases caen en la categoría de exclamación al igual que las interrogación. De la misma manera, cuando una pregunta comienza con por qué? La palabra 'que' lleva el acento.
These phrases fall in the category of exclamation the same as interrogation. The same way when you begin a question with "por qué?" The word "que" carries an accent.
