Lesson

In theory, qué and cuál(es) are equivalent to what and which in English, respectively. Although this is true in most cases, there are a few exceptions.

The feeling

¿Qué? feels like asking about something general. For instance, if we ask ¿qué quieres para comer? we're not thinking about a specific kind of food, we're referring to any kind of food you might think of.

On the other hand, when we ask ¿cuál?, a limited set of choices comes to mind. Going back to the example, if we knew there were only two possible meals available, like salad or pasta, then the question would be ¿cuál quieres comer?

How "ser" determines the use of "qué" and "cuál"

The usage of these interrogative pronouns varies in a very special way specifically when we use them with the verb ser. Let’s see how.

Qué + ser + noun: definitions

When we use this combination, what we expect from the answer is the definition of something. Generally, the nouns used in these kind of questions are preceded by an indefinite article like un, una, unos, unas or demonstratives like eso, esa, esto, este, etc.

• ¿Qué es un palíndromo?

  What's a palindrome?
• Un palíndromo es una palabra, frase o número que se lee igual al derecho y al revés.

  A palindrome is a word, phrase, or number read the same way backwards and forwards.

• ¿Qué es esa cosa tan rara que está sobre la mesa?

  What's that weird thing on the table?
• Eso es un experimento que hice para mi proyecto de ciencias.

  That’s an experiment I did for my science project.

Cuál(es) + ser + noun: information

Cuál can be used to ask for specific information when combined with the verb ser.

• ¿Cuál es tu nombre?

  What’s your name?
• Mi nombre es Julián.

  My name is Julián.

• ¿Cuál era tu película favorita cuando eras un niño?

  What was your favorite movie when you were a kid?
• Mi película favorita era El Rey León.

  My favorite movie was The Lion King.

Is it possible to get specific information with "qué + ser"?

Yes. There are three ways we can use qué + ser to get specific information:

Qué + ser + lo + adjective

Qué + ser can be used to ask for specific information just like cuál, but it uses the construct lo + adjective to produce a very general noun -like cosa (thing) or parte (part)- that doesn't need to be stated explicitly, but rather just described with an adjective. This process is called nominalization (sustantivación in Spanish).

• ¿Qué fue lo último que él dijo?

  What was the last thing he said?

In this example, the word cosa isn’t necessary (although it is in English) but if we decided to include it, then we would have to use cuál. Crazy! We know!

• ¿Cuál fue la última cosa que él dijo?

  What was the last thing he said?

In a situation where Merly and Michael are already talking about movies, she asks him:

• ¿Qué es lo mejor que has visto?

  What’s the best (movie) you’ve seen?

She knows they’re talking about movies, so she doesn’t need to use that word explicitly. However, if she decides to use it, then the question is:

• ¿Cuál es la mejor película que has visto?

  What’s the best movie you’ve seen?

Let’s make this clearer with two more examples:

• ¿Qué fue lo más divertido del viaje?

  What was the most fun part of the trip
• ¿Cuál fue la parte más divertida del viaje?

  What was the most fun part of the trip?

• ¿Qué ha sido lo peor que has hecho?

  What’s been the worst thing you’ve done?
• ¿Cuál ha sido la peor cosa que has hecho?

  What’s been the worst thing you’ve done?

Qué + ser + lo que

Another case where it’s possible to use qué + ser to ask for specific information is when it is used with the relative pronoun lo que.

• ¿Qué fue lo que él dijo?

  What was it that he said?
• Él dijo que estaba cansado.

  He said he was tired.

But if we use more specific relative pronouns such us el que, la que, los que, las que we need to use cuál + ser.

For instance, if Andrea shows Merly a group of books, she could ask:

• ¿Cuál fue el que leíste?

  Which one did you read? / What was the one that you read?
• Yo leí el libro azul.

  I read the blue one.

Let’s compare them one more time:

• ¿Qué fue lo que escuchaste?

  What did you hear? / What was it that you heard?

Speaking about a specific group of songs:

• ¿Cuál fue la que escuchaste?

  Which one did you listen to? / What was the one that you listened to?

Preposition + qué + ser

When the question starts with a preposition, it’s possible to use qué + ser to get information. Let’s see:

• ¿Para qué es este tablero?

  What is this board for?
• Es para jugar ajedrez.

  It’s for playing chess.

• ¿Sobre qué es la conferencia?

  What is the conference about?
• La conferencia es sobre el calentamiento global.

  The conference is about global warming.

"Qué" and "cuál" with nouns

We can use qué and _cuál before a noun and both will be correct, but there is a clearly perceptible change in the sensación (feeling) that it produces to native speakers. Let’s see:

With qué, it is implied that there is an indefinite amount of books (like "what").

• ¿Qué libro quieres?

  What book do you want?

With cuál, it is implied that there is a limited selection of books (like "which").

• ¿Cuál libro quieres?

  Which book do you want?

In questions where verbs other than ser are used, qué means what and cuál(es) means which:

• ¿Qué estás comiendo?

  What are you eating?
• ¿Qué hiciste ayer?

  What did you do yesterday?
• ¿Cuál de los dos vestidos debería comprarme?

  Which of these two dresses should I buy?

So just remember: you need to pay special attention when using qué and cuál with the verb ser. If you keep these rules in mind, you'll find that it's really not that confusing after all!

To practice, check out our exercises or listen to our podcast, this time with a special guest!