Interrogative Qual / Quais: Which

Qual (plural quais) is usually translated as which, and that translation works most of the time. But the real meaning of qual is more precise: it asks you to pick one out of a set. That selection idea is the key to using it correctly — and it explains a difference from English that catches almost every learner, including the way Brazilians ask for your name.

The core idea: selection from a set

Qual asks the listener to identify a specific item among several possibilities, whether those possibilities are stated out loud or just understood from context.

In the first example, the set is explicit (blue or red). In the second and third, the set is implied — there is a known range of options, dishes, books, and you are being asked to single one out. That is the heart of qual: not what in general, but which one, specifically.

qual vs quais: agreeing in number

This is where qual differs from invariable quem and o que: it has a plural form, quais. Use qual when you expect a single answer and quais when you expect more than one.

There is no gender change — qual and quais are the same for masculine and feminine. Only number matters, and you almost always make it match the verb and the expected answer: qual é (singular), quais são (plural).

The big one: Qual é o seu nome? (not "Que é...")

Here is the single most important thing on this page. When you ask someone's name, Brazilians use qual, not que or o que:

In English these all use what — what's your name, what's your number, what's your address — so English speakers instinctively reach for o que and produce the wrong O que é o seu nome? That sentence is understandable but clearly non-native, and it is one of the clearest giveaways of an English speaker.

Why qual? Because Portuguese treats a name, a number, or an address as one specific value selected out of all possible values. Your name is which name, out of every name there is — a selection. English does not think this way; it just asks what. Portuguese reserves o que for asking about the nature or definition of something (O que é um nome? = What is a name? — asking for a definition), and uses qual for picking your particular one out of the set. So:

• Qual é o seu nome? → Which name is yours? → asks you to supply your name. (correct, everyday)
• O que é um nome? → What is a name? → asks for the definition of the concept. (a philosophy question)

When English "what" becomes Portuguese "qual"

The name example is part of a broader pattern: whenever English what is really asking you to single out one item from an implied set, Portuguese prefers qual.

In each, you are selecting a specific answer out of a field of possibilities (one capital out of all cities, one problem out of all things, one difference out of all differences). Compare with genuine definition questions, which keep o que: O que é a fotossíntese? (What is photosynthesis? — define it). The test is: am I asking which specific one? → qual. Am I asking what is the nature/meaning of this? → o que.

qual + noun vs que + noun

You can put a noun after qual (qual livro), and it overlaps with que + noun (que livro). Both translate as which/what book, but there is a nuance:

• que livro → open, unrestricted: what book (at all)?
• qual livro → out of a known group: which book (of these)?

In practice the line is soft, and in everyday Brazilian speech qual + noun is extremely common where the choice is from a limited set. When the set is clearly bounded (these buses at this stop), qual feels more natural. (For the full que vs o que picture, see the companion page.)

Quick reference

Common Mistakes

The number-one error. A name is a value selected from a set, so Portuguese uses qual. O que é o seu nome? sounds like you are asking for the definition of the word name.

Expecting more than one answer means quais, and the verb is plural (são) to match.

A single answer takes singular qual with é. Don't pluralize just because the topic feels big.

Phone numbers, like names, are selected values — use qual. If you genuinely meant what is a telephone? (the device), that would be O que é um telefone?

There is no quala / qualo. Qual never changes for gender — only qual (sg.) vs quais (pl.).

Key Takeaways

• Qual = which, but its real job is selecting one item from a set.
• Plural is quais; there is no gender change. Match the verb: qual é, quais são.
• Use qual — not o que — for name, number, address, capital, problem, difference: Qual é o seu nome?
• Reserve o que for definition questions (O que é...? = What is... [by nature]?).