Quin llibre vols?

Quin means which when it is placed before a noun.

So in Quin llibre vols?, quin goes with llibre and means which book.

By contrast, què means what and usually stands on its own, not directly before a noun.

• Quin llibre vols? = Which book do you want?
• Què vols? = What do you want?

So a useful rule is:

• quin / quina / quins / quines
  • noun = which ...?
• què = what?

Because quin has to agree with the noun it refers to.

Llibre is:

• masculine
• singular

So the correct form is quin.

The full set is:

• quin = masculine singular
• quina = feminine singular
• quins = masculine plural
• quines = feminine plural

Examples:

• Quin llibre vols? = Which book do you want?
• Quina pel·lícula vols veure? = Which film do you want to watch?
• Quins llibres vols? = Which books do you want?
• Quines pel·lícules vols veure? = Which films do you want to watch?

Llibre is simply the noun: book.

In this sentence, quin llibre works together as a question phrase meaning which book.

So the structure is:

• quin = question word/determiner
• llibre = noun
• vols = verb

Vols is the 2nd person singular present tense form of the verb voler, which means to want.

So vols means you want.

A few present-tense forms of voler are:

• jo vull = I want
• tu vols = you want
• ell/ella vol = he/she wants
• nosaltres volem = we want
• vosaltres voleu = you all want
• ells/elles volen = they want

So Quin llibre vols? is addressing one person informally.

Because Catalan often leaves out subject pronouns when they are not needed.

The verb form vols already tells you the subject is tu (informal singular you), so tu is usually omitted.

That means:

• Quin llibre vols?
• Quin llibre vols tu?

both mean the same thing, but the second one sounds more emphatic, contrastive, or conversational depending on context.

This is very common in Catalan, just as in Spanish or Italian.

Catalan does not use a helper verb like English do to form ordinary questions.

English says:

• Which book do you want?

Catalan simply uses the normal verb:

• Quin llibre vols?

So there is no equivalent of English do here.

That is one of the big differences between English and Catalan question formation.

Yes. The word order is very natural in Catalan.

The sentence begins with the question phrase quin llibre and then follows with the verb vols:

• Quin llibre
  • vols

This is a standard pattern in Catalan for information questions.

Catalan does not usually need inversion like English does. English changes the structure to:

• Which book do you want?

Catalan keeps it much simpler:

• Quin llibre vols?

The interrogative word at the start already signals that it is a question.

Yes, absolutely.

Quin llibre vols tu? is grammatical, but tu is added for emphasis.

You might use tu if:

• you are contrasting one person with another
• you want to stress who is being asked
• the conversation is especially expressive

For example:

• Jo vull aquest. Quin llibre vols tu? = I want this one. Which book do you want?

Without emphasis, the shorter Quin llibre vols? is more neutral and common.

It is informal singular, because vols corresponds to tu.

If you want to be more formal, Catalan commonly uses vostè or vostès, depending on the variety and situation. The verb changes accordingly.

Examples:

• Quin llibre vol? = Which book do you want? (formal singular)
• Quin llibre voleu? = Which book do you want? (plural, or formal singular in some varieties/settings)

So Quin llibre vols? is what you would say to:

• a friend
• a child
• someone you know well
• an informal singular listener

No. After quin, you normally do not use an article.

So you say:

• Quin llibre vols?

not:

• Quin el llibre vols?

This is like English which book, not which the book.

The interrogative determiner quin already introduces the noun, so no article is needed there.

A simple approximate pronunciation is:

• quin ≈ keen
• llibre ≈ LYEE-bruh or YEE-bruh depending on accent and how strongly the ll is pronounced
• vols ≈ bols or vols with a short o

A rough whole-sentence approximation is:

keen LYEE-bruh bols?

A few notes:

• ll in Catalan can vary by dialect; in many accents it sounds somewhat like ly
• the v in Catalan is often pronounced like b
• the final s in vols is pronounced

If you want very natural pronunciation, listening to native audio is especially helpful for llibre.

In natural English, Which book do you want? and What book do you want? can sometimes overlap.

But in Catalan, quin llibre specifically points to which book—usually implying a choice among books, whether clearly stated or just understood from context.

If you ask more generally What do you want?, that would be:

• Què vols?

So quin llibre vols? is more specific than què vols? because it already tells us the thing being asked about is a book.