In short

A relative clause lets you add information about a noun without starting a new sentence: instead of “I bought a book. The book was expensive”, you say “the book that I bought was expensive”. Portuguese does this with a small set of relative words - above all que, plus quem for people after a preposition, and onde for places. Two habits from English will trip you up and both are fixed by one rule: in Portuguese you never drop the relative, and you always put any preposition in front of it. Learn to build “preposition + quem/que” and most relative clauses fall into place.

The rule

que - the all-purpose relative

que is invariable (never changes for gender or number) and does the vast majority of the work. It refers to people or things and can be the subject or the object of its clause.

• Subject: A senhora que mora ao lado é médica. (The lady who lives next door is a doctor.)
• Object: O comboio que apanhei estava cheio. (The train I caught was full.)

Notice the second English sentence has no relative word at all - “the train I caught”. Portuguese cannot do that. The que is obligatory: o comboio que apanhei, never o comboio apanhei.

quem - people, after a preposition

quem refers only to people and is used mainly when a preposition is involved. First decide which preposition the verb needs (falar com, gostar de, escrever a, confiar em), then place it before quem:

• A colega com quem partilho o gabinete mudou-se. (The colleague I share the office with…)
• O professor a quem escrevi ainda não respondeu. (The teacher I wrote to…)

With an explicit antecedent and no preposition, use que, not quem: a rapariga que conheci (the girl I met), not a rapariga quem conheci. quem also works with no antecedent at all, meaning “whoever / the one who”, and then the verb is third-person singular: Quem não arrisca não petisca.

onde - places

onde means “where” and points to a place. It is interchangeable with em que: a casa onde vivo = a casa em que vivo. For motion towards a place use aonde (aonde vais?), and por onde for “through which”, donde / de onde for “from where”. Use onde only for real, physical places - for time, use em que: o dia em que nos conhecemos (the day we met), not o dia onde….

o que - a whole idea

Use o que (“what / which”) to refer to a complete idea rather than a single noun. It sums up the previous clause or stands for an unspecified thing:

• Ele chegou atrasado, o que irritou toda a gente. (…, which annoyed everyone.)
• Não percebi o que disseste. (I didn’t get what you said.)

After tudo, the relative is o que: tudo o que sei (everything I know).

Defining vs adding information

No comma = a defining clause that tells you which one: Os alunos que estudaram passaram (only the ones who studied). With commas, the clause just adds a detail: O meu irmão, que vive em Lisboa, vem cá amanhã (I have one brother; by the way, he lives in Lisbon).

para and por can also introduce relatives, but they collide with the conjunctions para que (“so that”) and porque (“because”), so speakers often switch to o qual there - that form, and the possessive cujo, are the subject of the next relatives lesson.

Forms & patterns

The core relatives:

Building “preposition + relative” - the preposition always comes first:

Examples

Common mistakes

• o homem que falei com ele -> o homem com quem falei - put the preposition before the relative and never add a second pronoun; Portuguese does not strand prepositions or double the reference like English “the man I spoke to”.
• o livro li ontem -> o livro que li ontem - the relative is obligatory; Portuguese never drops it the way English drops “that” in “the book I read”.
• a rapariga quem conheci -> a rapariga que conheci - with a stated antecedent and no preposition, use que; quem needs either a preposition or no antecedent at all.
• a casa onde vivo nela -> a casa onde vivo - do not add a resumptive “nela / nele / lá” after onde or em que; the relative already carries that meaning.
• a cidade que nasci -> a cidade onde nasci (or em que) - a place needs onde / em que, not bare que.
• o problema o que temos -> o problema que temos - use o que only for a whole idea or “the thing that”, never straight after a concrete noun.

Tips

• One rule solves most cases: find the preposition the verb requires, then say it out loud before the relative - gostar de + film = o filme de que gosto; gostar de + person = a pessoa de quem gosto.
• After a preposition, the default split is simple: quem for people, que (or onde for places) for things.
• To comment on a whole situation, reach for , o que: Choveu o dia todo, o que estragou o passeio.
• quem with no antecedent takes a singular verb: Quem chegar primeiro abre a porta (whoever arrives first opens the door).
• Commas change the meaning: os passageiros que tinham bilhete = only some; os passageiros, que tinham bilhete, = all of them, and by the way they had tickets.
• In Brazil: tudo que (without the o) is very common in speech; European Portuguese keeps the article - tudo o que.