Relative pronouns refer back to a term already mentioned and link two pieces of information in a single clause. They replace that antecedent and introduce a subordinate clause that describes, identifies, or specifies it. For this reason, they frequently appear in constructions that require precision, such as Demonstrative Pronouns, Possessive Pronouns, and Interrogative Pronouns.

Que is the most general relative pronoun and serves for people, things, and ideas in colloquial Portuguese. Quem refers to people and normally appears after a preposition. Onde indicates place, quando indicates time, and quanto expresses quantity or value, often with the sense of everything that. The form o que can appear without an expressed antecedent, functioning as a nominalization.

IdeiaIdea.	ExemploExample.
Que retoma pessoas, coisas ou ideias em registro comum.Que refers to people, things, or ideas in ordinary usage.	O livro que li era antigo.The book I read was old.
Quem retoma apenas pessoas e costuma vir após preposição.Quem refers to people only and tends to appear after a preposition.	A amiga de quem falei chegou cedo.The friend whom I mentioned arrived early.
Onde retoma lugar.Where refers to place.	A cidade onde nasci mudou muito.The city where I was born has changed a lot.
Quando retoma tempo.Quando refers to time.	O ano em que nasceu foi importante.The year in which he was born was important.
Quanto retoma quantidade ou valor.Quanto refers to quantity or value.	Tudo quanto sei veio da experiência.Everything I know came from experience.
O que pode omitir o antecedente e criar uma ideia substantivada.O que can omit the antecedent and create a nominalized idea.	O que me surpreende é a rapidez.What surprises me is the speed.

The forms o qual, a qual, os quais and as quais are more formal relatives and vary in gender and number according to the antecedent. They appear mainly after a preposition, which makes them useful when the syntactic relation needs to be very clear. In colloquial speech, which tends to replace these forms more naturally, as also seen in the reading of Interrogative Pronouns.

IdeiaIdea.	ExemploExample.
O qual concorda com antecedente masculino singular.O qual agrees with the antecedent masculine singular.	O autor ao qual me refiro publicou muito.The author to whom I refer published a lot.
A qual concorda com antecedente feminino singular.A qual agrees with the feminine singular antecedent.	A ideia à qual volto é simples.The idea to which I return is simple.
Os quais concorda com antecedente masculino plural.Os quais agree with the masculine plural antecedent.	Os colegas com os quais falei concordaram.The colleagues with whom I spoke agreed.
As quais concorda com antecedente feminino plural.As quais agree with the feminine plural antecedent.	As razões pelas quais partimos eram claras.The reasons for which we left were clear.

Cujo, cuja, cujos and cujas indicate possession and agree with the possessed noun, not with the possessor. The form tends to appear in more careful registers and is less frequent in speech, which often prefers do qual or de quem. This relation is especially visible when compared with Possessive Pronouns.

IdeiaIdea.	ExemploExample.
Cujo concorda com o objeto possuído masculino singular.Cujo agrees with the possessed noun, masculine singular.	O autor cujo livro li é famoso.The author whose book I read is famous.
Cuja concorda com o objeto possuído feminino singular.Cuja agrees with the possessed noun, feminine singular.	A mulher cuja casa visitei mora aqui.The woman whose house I visited lives here.
Cujos concorda com o objeto possuído masculino plural.Cujos agrees with the possessed noun, masculine plural.	O músico cujos discos ouvi venceu.The musician whose records I listened to won.
Cujas concorda com o objeto possuído feminino plural.Cujas agrees with the possessed noun, feminine plural.	A jornalista cujas reportagens li recebeu prêmio.The journalist whose reports I read received an award.

When the verb or the name of the relative clause requires a preposition, it comes before the relative pronoun. This preposition does not disappear because the relative occupies the position of the resumed term. In many varieties of Portuguese, especially for time and a more neutral relation, it is preferred to use em que or equivalent forms instead of other constructions that are less natural.

IdeiaIdea.	ExemploExample.
A preposição exigida aparece antes do relativo.The required preposition appears before the relative.	A pessoa com quem falei chegou.The person with whom I spoke arrived.
A forma formal pode surgir após a preposição.The formal form may appear after the preposition.	A questão à qual respondi era difícil.The question to which I answered was difficult.
Em referências temporais, em que é muito frequente.In temporal references, em que is very frequent.	O dia em que viajamos foi chuvoso.The day on which we traveled was rainy.

The relative clause can be restrictive or explanatory, and the comma changes the meaning. Without commas, the relative clause restricts the antecedent and selects a specific element. With commas, the relative clause merely adds extra information about an already identified antecedent, as seen in constructions that also help interpret Reflexive Pronouns in context.

IdeiaIdea.	ExemploExample.
A relativa restritiva seleciona um referente específico.The restrictive relative clause selects a specific referent.	O carro que passou era vermelho.The car that passed was red.
A relativa explicativa acrescenta informação extra.The explanatory relative adds extra information.	O carro, que passou, era vermelho.The car, which passed, was red.
A presença de vírgulas altera o alcance do sentido.The presence of commas alters the scope of meaning.	A aluna que estudou passou.The student who studied passed.

In everyday Portuguese, que covers many functions that in more formal styles would be expressed by o qual, a qual, os quais and as quais. Cujo is also less common in speech and is frequently replaced by do qual, da qual, de quem or equivalent constructions. The preference for em que for time and for more direct prepositional solutions varies according to region and register.

RegiãoRegion.	Palavra ou ExpressãoWord or Expression.	Definição RegionalRegional Definition.	ExemploExample.
PortugalPortugal.	QueThat/Which.	Forma muito usada na fala e na escrita comum para retomar pessoas e coisas.A form widely used in speech and in everyday writing to refer to people and things.	O livro que li era claro.The book I read was clear.
Registo formalFormal Register.	O qualThe one which.	Forma mais cuidadosa, comum após preposição e em contextos escritos.A more careful form, common after a preposition and in written contexts.	A regra pela qual sigo é antiga.The rule by which I follow is old.
Fala correnteColloquial Speech.	CujoWhose.	Forma menos frequente na oralidade e muitas vezes substituída por outra construção.A less frequent form in speech and often replaced by another construction.	A casa de quem falei fica perto.The house I spoke of is nearby.
Uso amploBroad Use.	Em queIn which.	Forma muito frequente para referência temporal ou locativa.A very frequent form for temporal or locative reference.	O momento em que cheguei foi decisivo.The moment in which I arrived was decisive.

Relative pronouns link clauses and refer back to an antecedent to characterize, locate, quantify, or mark possession. Que is the most general relative pronoun, quem is used for people, where and when organize relations of place and time, quanto expresses quantity, and o que allows omitting the antecedent. The forms o qual, a qual, os quais and as quais give greater formal precision; cujo marks possession, and the comma distinguishes between restrictive and explanatory information.