English collapses several ideas into one tiny word: for. "I bought this for you," "I paid twenty euros for it," "I worked for three hours," "I did it for you (in your place)," "I'm going for the weekend." Portuguese splits these meanings across two prepositions, por and para, and picking the wrong one changes what the sentence says. Getting this pair right is one of the clearest signals that you have moved past beginner Portuguese.
The core intuition is compact: por looks backwards — at the cause, the agent, the path travelled, the thing exchanged. Para looks forwards — at the destination, the purpose, the recipient, the deadline. If you can locate your sentence on that cause-vs-goal axis, the choice usually makes itself.
The quick answer
Use por for cause, reason, exchange, agent, means, passage through, and acting in someone's place. Use para for destination, purpose, recipient, deadline, opinion, and orientation towards. When in doubt, ask yourself: am I describing why or how this happened (por), or where it is headed (para)?
Por — the backward-looking preposition
Cause and motive
When por answers why?, it names the cause, motive, or reason. English often uses because of, out of, or for (the sake of).
Fiz isto por ti.
I did this for you (for your sake / because of you).
Fechei a janela por causa do barulho.
I closed the window because of the noise.
Notice the last example: por causa de is the full causal locution. A plain por suffices when the cause is abstract (por amor, por medo, por curiosidade), but for a concrete cause PT-PT usually reaches for por causa de.
Exchange and price
Any time something trades hands for something else — money, effort, a swap — you want por.
Comprei o telemóvel por 300 euros em segunda mão.
I bought the phone for 300 euros second-hand.
Trocas o lugar comigo pelo lugar ao pé da janela?
Will you swap seats with me for the one by the window?
Vendeu o carro por metade do que pagou.
He sold the car for half of what he paid.
The passive agent — "by"
In a passive sentence, the person or thing that performs the action is introduced by por. This is one of the few places where English by translates mechanically into Portuguese.
O livro foi escrito por uma jornalista portuguesa.
The book was written by a Portuguese journalist.
A janela foi partida pelo vento durante a noite.
The window was broken by the wind during the night.
Movement through a space
When you pass through or along somewhere rather than ending up there, the preposition is por. Think of a route, not a destination.
Passámos pelo parque no caminho para casa.
We went through the park on the way home.
O comboio passa por Coimbra às oito da manhã.
The train passes through Coimbra at eight in the morning.
Entrei por aquela porta e saí pela outra.
I came in through that door and went out through the other one.
Duration (limited)
Por can mark duration, but in modern PT-PT this is the minority choice — durante or a bare time phrase is usually preferred.
Vou estar fora por uma semana.
I'll be away for a week.
Vivi em Berlim durante três anos.
I lived in Berlin for three years. (durante is more idiomatic here)
Multiplier / rate
Por expresses per or times per — a rate across a unit.
Tomo este comprimido duas vezes por dia.
I take this pill twice a day.
O ginásio custa cinquenta euros por mês.
The gym costs fifty euros a month.
By means of
To say by car, by post, by phone, por names the channel or instrument.
Mandei os documentos por correio registado.
I sent the documents by registered post.
Combinámos tudo por mensagem.
We arranged everything by text message.
Acting in someone's place (a distinctively PT-PT nuance)
This is the use that English speakers most often miss. Por can mean in place of, on behalf of, so that they don't have to. The doer is you; the beneficiary is them, and you are stepping into a role that was theirs.
Não te preocupes, eu falo por ti na reunião.
Don't worry, I'll speak for you (in your place) at the meeting.
Ele assinou por mim, porque eu estava no estrangeiro.
He signed for me (on my behalf), because I was abroad.
A avó vai buscar os miúdos por ela hoje.
Grandma's picking up the kids for her (in her stead) today.
This is the subtle opposite of para ti — see the critical contrast below.
Para — the forward-looking preposition
Destination
Physical destination of movement — going to somewhere — takes para.
Vou para casa, estou cansadíssima.
I'm going home, I'm exhausted.
O comboio para o Porto sai daqui a dez minutos.
The train to Porto leaves in ten minutes.
Recipient
The person or thing a gift, letter, favour, or action is for — the intended recipient — takes para.
Esta prenda é para ti, abre lá!
This present is for you — go on, open it!
Trouxe um bolo para os teus pais.
I brought a cake for your parents.
Deadline / by when
When you're saying by Friday, for tomorrow, by the end of the month, you need para.
O relatório tem de estar pronto para amanhã.
The report has to be ready by tomorrow.
Purpose / intended use
What something is for, the function or goal, is introduced by para.
Este dinheiro é para a renda do mês que vem.
This money is for next month's rent.
Comprei um livro para aprender português.
I bought a book (in order) to learn Portuguese.
Preciso de uma chave de fendas para arranjar isto.
I need a screwdriver to fix this.
Before an infinitive, para means in order to: para aprender, para arranjar, para não esquecer.
Opinion — "in my view"
For me, as far as I'm concerned — the speaker's perspective — takes para.
Para mim, este foi o melhor filme do ano.
For me, this was the best film of the year.
Para ela, isso não faz sentido nenhum.
For her (as she sees it), that makes no sense.
Comparison ("considering")
Para can mean for / considering, flagging that something is surprising relative to a norm.
És muito alto para a tua idade.
You're very tall for your age.
Para um iniciante, falas muito bem português.
For a beginner, you speak Portuguese very well.
Orientation — "facing"
A window or a balcony para o mar, a chair virada para a porta — para signals what something faces or is turned towards.
O apartamento tem uma varanda virada para o rio.
The flat has a balcony facing the river.
The critical contrast: por ti vs para ti
English collapses these with "for you", but Portuguese pulls them apart sharply.
Faço isto por ti.
I do this for you — because of you, for your sake, or in your place.
Faço isto para ti.
I do this for you — so that you have it, as the recipient.
The first sentence says I'm motivated by you or I'm doing this so you don't have to. The second says I'm doing this and the product is destined for you. In a real situation:
- Faço o jantar *por ti — *I'm cooking dinner for you = because you're tired / so you don't have to / as a favour motivated by you.
- Faço o jantar *para ti — *I'm cooking dinner for you = and you're the one who's going to eat it.
Often both are true and either works. But when a native speaker chooses between them, they are saying something different.
Vou ao supermercado por ti.
I'll go to the supermarket for you (in your place — so you don't have to).
Comprei este chocolate para ti.
I bought this chocolate for you (you're the recipient).
Agradeço tudo o que fizeste por mim.
I'm grateful for everything you did for me (on my behalf, for my sake).
Isto é para mim ou para ti?
Is this for me or for you? (who is it destined for)
Contractions with articles
Por contracts with the definite article. These contractions are obligatory — you cannot say por o, only pelo.
| o | a | os | as | |
|---|---|---|---|---|
| por + | pelo | pela | pelos | pelas |
Passámos pelo centro antes de chegar.
We went through the centre before arriving.
O livro foi traduzido pela editora francesa.
The book was translated by the French publisher.
Para does not contract with the definite article in standard written PT-PT. You write and say para o, para a, para os, para as in full.
Este presente é para a tua mãe.
This present is for your mother.
Vou para o Porto amanhã.
I'm going to Porto tomorrow.
Decision table
| Use case | Preposition | Example |
|---|---|---|
| Cause / reason ("because of, out of") | por | Fi-lo por amor. |
| Exchange / price | por | Comprei por 50 euros. |
| Agent of a passive verb ("by") | por | Foi feito por ele. |
| Passage through a space | por | Passei pelo Porto. |
| Rate / per | por | Duas vezes por dia. |
| By means of | por | Falámos por telefone. |
| In place of / on behalf of | por | Assinei por ele. |
| Duration (less common in PT-PT) | por | Por uma semana. |
| Destination | para | Vou para casa. |
| Recipient | para | É para ti. |
| Deadline / by when | para | Para amanhã. |
| Purpose / intended use | para | Dinheiro para a renda. |
| Purpose before infinitive ("in order to") | para | Para aprender. |
| Opinion ("for me") | para | Para mim, é bom. |
| Comparison ("for / considering") | para | Alto para a idade. |
| Orientation / facing | para | Virado para o mar. |
Walking through tricky examples
1. Trabalho _ uma empresa alemã. — Working for an employer? That's your goal/destination of employment, so para: Trabalho *para uma empresa alemã.*
2. Fiz isto _ ti porque sabia que estavas ocupada. — I stepped in in your place, motivated by you. Por: Fiz isto *por ti...*
3. O bolo é _ ti. — Recipient. Para: O bolo é *para ti.*
4. O quadro foi pintado _ Amadeo de Souza-Cardoso. — Agent of a passive. Por: foi pintado *por Amadeo...*
5. Dá-me isso _ eu ver. — Purpose before an infinitive (so that I can see). Para: Dá-me isso *para eu ver.*
6. Passei _ tua casa e não estavas. — Movement through. Por: Passei *pela tua casa...*
7. Pagámos quinze euros _ pessoa. — Rate per unit. Por: quinze euros *por pessoa.*
8. Tenho de entregar o trabalho _ sexta. — Deadline. Para: ...entregar o trabalho *para sexta.*
9. _ mim, o melhor restaurante é o do bairro. — Opinion. Para: Para mim, o melhor...
10. Obrigado _ tudo o que fizeste. — This is a common trap. Obrigado *por tudo is the idiomatic PT-PT: you are thanking *because of what was done, not towards something.
Common mistakes
❌ Obrigado para a tua ajuda.
Incorrect — thanks is always *por* the thing you're grateful for.
✅ Obrigado pela tua ajuda.
Thanks for your help.
❌ Vou pra casa. / Isto é pra ti.
Non-standard in PT-PT — *pra* and *pro* are colloquial Brazilian contractions and are not used in European Portuguese.
✅ Vou para casa. / Isto é para ti.
I'm going home. / This is for you.
❌ Paguei para o bilhete 20 euros.
Price/exchange is *por*, not *para*.
✅ Paguei o bilhete por 20 euros. / Paguei 20 euros pelo bilhete.
I paid 20 euros for the ticket.
❌ O romance foi escrito para José Saramago.
Agent of a passive is *por*; *para* would mean the book was written *for him* (as a recipient).
✅ O romance foi escrito por José Saramago.
The novel was written by José Saramago.
❌ Fui no supermercado para ti porque estavas doente.
If you mean 'in your place / so you didn't have to', the preposition is *por*.
✅ Fui ao supermercado por ti porque estavas doente.
I went to the supermarket for you (in your stead) because you were ill.
❌ Estudo português por trabalhar em Lisboa.
Purpose before an infinitive is *para*, not *por*.
✅ Estudo português para trabalhar em Lisboa.
I'm studying Portuguese (in order) to work in Lisbon.
❌ Tenho de acabar isto por amanhã.
Deadline — that's *para*.
✅ Tenho de acabar isto para amanhã.
I have to finish this by tomorrow.
Key takeaways
- Por looks backward: cause, agent, exchange, path, rate, on behalf of.
- Para looks forward: destination, recipient, deadline, purpose, opinion, orientation.
- Por ti = because of / for the sake of / in place of you. Para ti = destined for you.
- Por contracts with the definite article → pelo, pela, pelos, pelas. Para stays in full: para o, para a. Pra/pro is Brazilian and not used in PT-PT.
- Obrigado por, not obrigado para. It is the most common error and always gives the non-native speaker away.
Related Topics
- por vs. para: The Classic PairA2 — The definitive PT-PT comparison of por and para — cause vs. purpose, agent vs. recipient, route vs. destination, duration vs. deadline, and the subtle cases that trip up every learner.
- The Preposition porA2 — Uses of the preposition por — agent, cause, means, route, duration, and its obligatory contractions pelo/pela.
- The Preposition paraA1 — Uses of the preposition para — purpose, destination, recipient, deadline, comparison, and the para vs. por distinction.
- Contractions with porA2 — How por contracts obligatorily with definite articles to produce pelo, pela, pelos, and pelas — with historical notes and what does not contract.
- Verbs and Their PrepositionsB1 — A reference list of which Portuguese verbs require which prepositions before their complement — the lexical pairings that determine whether your sentence is grammatical.