Question words and word order
There are two ways to ask in Spanish: lift your voice at the end of a statement, or open with a question word — qué, quién, dónde, cómo, cuándo, cuánto, por qué. Every one of those words wears an accent mark, and the accent is doing real work: it is the whole difference between qué ('what?') and que ('that'). Wrap the sentence in ¿ and ?, let the verb come before the subject, and you are asking.
Ask with your voice, answer with sí or no
The lightest question is a statement said upward. Tú vives en Lima. turns into ¿Tú vives en Lima? — same words, new melody, plus the two marks. The opening ¿ is not decoration; it warns your eyes that a question is coming before you get to the end of the line, which is exactly why Spanish bothers with it. Answer with sí or no. And if the answer is no, you will say no twice: No, no vivo en Lima. The first no is the answer, the second one sits in front of the verb and does the negating. Alone, No vivo en Lima is simply 'I don't live in Lima.'
The question words
qué = what, which. quién = who, and for a group quiénes: ¿Quiénes son ellos? dónde = where; glue a preposition on the front to aim it — de dónde (where from), a dónde or adónde (where to, for the movement verbs coming soon). cómo = how. cuándo = when. cuánto = how much, and it agrees like an adjective when it lands on a noun: cuántos hermanos, cuánta fruta, cuántas flores. por qué = why — literally 'through what', two words.
One accent, two different words
Take the accent off a question word and you get a different word entirely. qué (what?) ↔ que (that): Dice que su casa está acá. dónde (where?) ↔ donde (the place where): La casa donde vivo es pequeña. cómo (how?) ↔ como (like, as — and also 'I eat'): Ella canta como su mamá. The accent stays even when the question is buried inside a longer sentence: Camila pregunta dónde vives. Nobody is saying ¿…? out loud there, but it is still a question, so it still gets the mark.
por qué asks, porque answers
Two words with an accent ask: ¿Por qué estudias español? One word without an accent answers: Porque mi familia vive en México. They sound almost identical out loud — the question stresses the second half, the answer runs together — so the spelling is what keeps them apart on paper. Get in the habit early: a question mark in the sentence means por qué; an explanation means porque.
The verb goes first
Statement: Camila vive en Bogotá. Question: ¿Dónde vive Camila? The subject slides behind the verb — not ¿Dónde Camila vive?, which sounds like a translation. Same in a yes/no question: ¿Vive Camila acá? Most of the time you drop the pronoun altogether and the question is two words long: ¿Qué haces?, ¿Dónde trabajas?, ¿Cuándo cantan? You put ustedes back in only when you need to make clear you mean the group: ¿Cuándo cantan ustedes?
qué tan and qué tanto
To ask 'how big', 'how fast', 'how far', Latin America reaches for qué tan in front of an adjective or adverb: ¿Qué tan grande es la ciudad?, ¿Qué tan rápido hablas? With a verb or an uncountable amount it becomes qué tanto: ¿Qué tanto trabajas? = how much do you work. cuánto is still there for countable things and for prices — ¿Cuánto es? is what you say at the market when you want the number — but qué tan is the one you will hear from Monterrey to Santiago, and it has no single English word behind it.
When you didn't catch it: ¿Cómo?
You will need this on day one. If someone says something you missed, the pan-regional repair is ¿Cómo? — 'sorry?'. In Mexico you will also hear ¿Mande?, especially when someone calls your name and you answer. A bare ¿Qué? on its own is understood everywhere but lands hard, close to English 'what?!' snapped at a stranger, so keep ¿Cómo? as your default and you will never sound rude. To ask someone to slow down: ¿Puede hablar más despacio? — or, softened the way the region likes, despacito.
The little a before a person
When the thing your verb acts on is a person — or a dog the family loves — Spanish puts a in front of it. Veo la casa, but Veo a Camila. Escucho música, but Escucho a mi mamá. There is nothing in English to translate it with; it simply marks 'this one is a human'. Things never take it: Compro frutas, Miro el mapa. The same a also points at direction, from one place to another: de la casa a la clase.
