The main rule
Open the clause with si (yes / no) or with the question word (qué, quién, cuál, dónde, cuándo, cómo, cuánto, por qué), always with its accent, and keep the normal statement order: No sé dónde vive. No "do", no question marks inside a statement. When the person in doubt is the one who would act, the question word can take an infinitive: No sé qué hacer.
What the clause starts with
| Opens with | Asks about | Example |
|---|---|---|
| si | yes or no | No sé si viene. (I don't know if he is coming.) |
| qué | what | Dime qué quieres para cenar. (Tell me what you want for dinner.) |
| quién, quiénes | who | No sé quién llama. (I don't know who is calling.) |
| cuál, cuáles | which one | No recuerdo cuál es su número. (I don't remember what his number is.) |
| dónde, adónde | where, where to | ¿Sabes dónde trabaja? (Do you know where she works?) |
| cuándo | when | No sé cuándo llegan. (I don't know when they arrive.) |
| cómo | how | Quiero saber cómo funciona. (I want to know how it works.) |
| cuánto, cuánta, cuántos, cuántas | how much, how many | No sé cuántos años tiene. (I don't know how old he is.) |
| por qué | why | No sé por qué llora. (I don't know why she is crying.) |
A preposition stays in front of the question word, as in English "to whom", but Spanish never moves it to the end: de dónde (where from), a quién, con quién, para qué (what for), desde cuándo, a qué hora. For example: No sé con quién habla, Quiero saber desde cuándo vive aquí.
Cuál picks one item from a known set: No sé cuál de los dos prefiere, cuál es su número. Before a noun the usual word is qué: No sé qué libro leer (in parts of Latin America you also hear cuál libro). You will also hear lo que instead of qué: No sé lo que quiere means the same as No sé qué quiere.
The contrast with English
English changes the word order in a direct question ("Where does he live?") and puts it back in an indirect one ("I don't know where he lives"). Spanish has no helper verb, so the indirect question is simply the direct one without its question marks: ¿Dónde vive? becomes No sé dónde vive. The subject is free, so No sé dónde vive Carmen and No sé dónde Carmen vive are both fine.
English "if" and "whether" are both si, and "whether or not" is si ... o no: No sé si viene o no. In Spanish, "that" and "what" sound the same, que and qué, and only the written accent tells them apart: Sé que viene (I know that he is coming) but No sé qué quiere (I don't know what he wants).
Examples
- No sé si Carmen viene a la cena. I don't know if Carmen is coming to dinner.
- ¿Sabes dónde vive Raúl? Do you know where Raúl lives?
- No recuerdo cuándo empieza la película. I don't remember when the film starts.
- Me pregunto por qué no contesta. I wonder why she isn't answering.
- Dime de dónde es tu familia. Tell me where your family is from.
- Quiero saber cuánto cuesta el alquiler. I want to know how much the rent is.
- Pregúntale a Inés si puede traer el postre. Ask Inés if she can bring the dessert.
- Voy a averiguar a qué hora sale el tren. I'm going to find out what time the train leaves.
- No tengo ni idea de qué decir. I have no idea what to say.
Si and sí, que and qué
Si without an accent is "if, whether"; sí with an accent is "yes". An indirect question always takes the plain one: No sé si viene. The other question words also carry an accent. The same word without the accent is a conjunction or a relative, not a question.
| Word | Statement or relative (no accent) | Indirect question (accent) |
|---|---|---|
| que / qué | Sé que viene. (I know that he is coming.) | No sé qué quiere. (I don't know what he wants.) |
| donde / dónde | Vivo donde trabajo. (I live where I work.) | No sé dónde trabaja. (I don't know where he works.) |
| cuando / cuándo | Llámame cuando llegues. (Call me when you arrive.) | No sé cuándo llega. (I don't know when he arrives.) |
| como / cómo | Hazlo como quieras. (Do it however you like.) | No sé cómo se hace. (I don't know how it is done.) |
| porque / por qué | Llora porque está cansada. (She is crying because she is tired.) | No sé por qué llora. (I don't know why she is crying.) |
Punctuation
When the main clause is a statement, the whole sentence is a statement: no question marks, even though a question is inside it. No sé dónde vive. When the main clause itself asks, the marks go around the whole sentence, from the start: ¿Sabes dónde vive? The opening ¿ is never put in front of the question word in the middle: ¿Sabes ¿dónde vive? is wrong.
Question word + infinitive
When the person who has the doubt is also the one who would act, Spanish uses the question word and an infinitive, as English does with "what to do": No sé qué hacer, No sé cómo llegar, No sé a quién llamar, No sé si ir. If someone else acts, use a finite verb: No sé qué hace Carmen.
Verbs that introduce them
The usual ones are saber and no saber, no recordar, querer saber, averiguar, preguntar, preguntarse, no tener ni idea de, and the commands dime and pregúntale. With preguntar the person asked is an indirect object: Le pregunto a Inés si tiene tiempo. After a past form such as preguntó, the tense of the clause usually shifts, as in reported speech: Me preguntó si tenía tiempo.
In everyday speech you often hear an extra que after preguntar: Me pregunta que si tengo tiempo, Me pregunta que dónde vivo. This is common and correct. Also, unlike the conditional si (Si viene, te aviso, never Si vendrá), the si of an indirect question takes any tense: No sé si viene, No sé si vendrá, No sé si va a venir.
Quick check for the accent
If the clause could stand alone as a direct question (¿Dónde vive?, ¿Qué quiere?), the word takes an accent. If it joins two ideas (Vivo donde trabajo), it does not.
Common mistakes
No sé donde vive.No sé dónde vive. A question word keeps its accent even inside a statement.No sé que quiere para cenar.No sé qué quiere para cenar. Meaning "what", not "that".No sé ¿dónde vive?No sé dónde vive. No question marks inside a statement.Le pido si tiene tiempo.Le pregunto si tiene tiempo. Pedir is to ask for something; preguntar is to ask a question.No sé si o no viene.No sé si viene o no. Whether or not: o no goes at the end.No sé porque llora.No sé por qué llora. Why is two words with an accent.No sé sí viene.No sé si viene. Sí with an accent means yes.
Frequently asked questions
How do you ask an indirect question in Spanish?
Start the clause with si for yes / no questions or with a question word for the rest, and use the normal verb form with no helper verb: No sé si viene, No sé dónde vive.
Do question words keep their accent in indirect questions?
Yes. Qué, quién, cuál, dónde, cuándo, cómo, cuánto and por qué are written with an accent whether the question is direct or indirect.
Do I use question marks in an indirect question?
Only if the main clause asks: ¿Sabes dónde vive? After a statement such as No sé there are none: No sé dónde vive.
What is the difference between si and sí?
Si means "if" or "whether" (No sé si viene). Sí with an accent means "yes".
Can I use the future after si in an indirect question?
Yes: No sé si vendrá. This differs from the conditional si, which does not take the future.
Is Me preguntó que si tenía tiempo correct?
Yes. The extra que is very common in speech and is not a mistake, though Me preguntó si tenía tiempo is the shorter form.