This is the page you bookmark. European Portuguese builds an unusually dense system of preposition contractions — de, em, a, and por all fuse with articles, demonstratives, pronouns, and neuter forms in ways that are often obligatory and occasionally optional. Get the table wrong and your writing stops sounding native in the first sentence. This page gathers every standard contraction in one place, flags what is mandatory versus optional, and notes where European and Brazilian Portuguese diverge.
There is almost no prose here on purpose. The tables are the content.
The four contracting prepositions
Only four Portuguese prepositions participate in the contraction system: de, em, a, and por. The others — com, sem, sob, sobre, para, até, entre, desde, contra — never contract with articles or pronouns in standard written Portuguese. (Spoken pra for para, prà for para a, and pró for para o are colloquial reductions, not formal contractions; see the para page.)
| Preposition | Contracts with |
|---|---|
| de | definite articles, indefinite articles (optional), demonstratives, personal pronouns (3rd), locative and neuter forms |
| em | definite articles, indefinite articles (optional), demonstratives, personal pronouns (3rd), neuter forms |
| a | definite articles, distal demonstratives (aquele family), neuter aquilo |
| por | definite articles only |
| com, sem, sob, sobre, para, até, entre, desde, contra | do not contract in standard writing |
Contractions with definite articles (obligatory)
This is the core table every learner needs. All sixteen forms are obligatory — there is no written alternative.
| o (m.sg.) | a (f.sg.) | os (m.pl.) | as (f.pl.) | |
|---|---|---|---|---|
| de | do | da | dos | das |
| em | no | na | nos | nas |
| a | ao | à | aos | às |
| por | pelo | pela | pelos | pelas |
O carro do meu pai está na garagem do prédio.
My father's car is in the garage of the building.
Cheguei ao escritório às oito pela primeira vez este mês.
I arrived at the office at eight for the first time this month.
The grave accent on à and às is not optional. It is the only written signal that a is a preposition + article rather than a bare article. Dropping it is a spelling error, not a stylistic choice.
Contractions with indefinite articles (optional except where noted)
The indefinite article contractions are the most flexible corner of the system. They are accepted in writing but never required — you may always write out the uncontracted form.
| um | uma | uns | umas | |
|---|---|---|---|---|
| de | dum (optional) | duma (optional) | duns (optional) | dumas (optional) |
| em | num (optional) | numa (optional) | nuns (optional) | numas (optional) |
| a | — | — | — | — |
| por | — | — | — | — |
A few editorial houses discourage dum and num in formal writing because the forms feel colloquial. In literary prose and academic writing you will see de um and em um more often. In news articles, emails, and fiction, dum and num are entirely normal.
Moro num apartamento pequeno mas muito bonito.
I live in a small but very pretty apartment.
Isto é a história duma família que atravessou o oceano em 1960.
This is the story of a family that crossed the ocean in 1960.
Preciso de um copo de água.
I need a glass of water.
Note that a and por give you no indefinite-article contractions at all. You always write a um médico, a uma amiga, por um motivo, por uma razão.
Falei a uma colega sobre o problema.
I spoke to a colleague about the problem.
Ficámos parados por uma hora inteira.
We were stopped for a whole hour.
Contractions with demonstratives (obligatory where possible)
This is where de and em are the busiest, and where a and por diverge sharply.
de + demonstratives
| Masculine | Feminine | Plural m. | Plural f. | Neuter |
|---|---|---|---|---|
| deste (this) | desta | destes | destas | disto |
| desse (that near you) | dessa | desses | dessas | disso |
| daquele (that over there) | daquela | daqueles | daquelas | daquilo |
em + demonstratives
| Masculine | Feminine | Plural m. | Plural f. | Neuter |
|---|---|---|---|---|
| neste | nesta | nestes | nestas | nisto |
| nesse | nessa | nesses | nessas | nisso |
| naquele | naquela | naqueles | naquelas | naquilo |
a + demonstratives (distal only)
The preposition a only contracts with the aquele family — never with este or esse. When it does contract, the result takes a grave accent, just like à.
| Masculine | Feminine | Plural m. | Plural f. | Neuter |
|---|---|---|---|---|
| àquele | àquela | àqueles | àquelas | àquilo |
Note the grave accent on all five forms: àquele, àquela, àqueles, àquelas, àquilo. Without the accent you have written the pronoun alone with no preposition.
Referiste-te àquele professor que tivemos em Coimbra?
Were you referring to that professor we had in Coimbra?
Não dês importância àquilo que ele disse.
Don't give importance to what he said.
With este and esse, the preposition a stays uncontracted: a este projeto, a essa ideia.
por + demonstratives
Por does not contract with any demonstrative. Every combination is two words.
Por isso é que te disse para levares o casaco.
That's why I told you to take a coat.
Por aquele caminho chegamos mais depressa.
By that road we'll arrive faster.
Contractions with personal pronouns (third person only)
Only de and em contract with the third-person subject pronouns ele, ela, eles, elas. The preposition a and por do not.
| Pronoun | de | em | a | por |
|---|---|---|---|---|
| ele | dele | nele | a ele | por ele |
| ela | dela | nela | a ela | por ela |
| eles | deles | neles | a eles | por eles |
| elas | delas | nelas | a elas | por elas |
No preposition contracts with the first- or second-person pronouns (eu, tu, nós, vós, vocês). You always write de mim, de ti, em mim, a mim, para ti, por nós.
Gosto dele mas às vezes perde a cabeça.
I like him, but sometimes he loses his temper.
Vi-me nela logo à primeira conversa.
I saw myself in her from the first conversation.
A decisão depende de ti.
The decision depends on you.
Contractions with locative adverbs and neuter pronouns
The preposition de alone contracts with the locative adverbs aqui, aí, ali:
| de + adverb | Contraction |
|---|---|
| de + aqui | daqui |
| de + aí | daí |
| de + ali | dali |
Sai daqui antes que eu me zangue.
Get out of here before I lose my temper.
Daí a uns minutos, ela telefonou.
A few minutes later, she called.
The preposition em does not fuse with these adverbs: em aqui is simply not used (you say aqui alone, since it already contains the location). A and por likewise do not contract with locatives.
Obligatory vs. optional: the quick verdict
Learners often want a single rule. Here it is:
Obligatory (you must contract, no written alternative):
- de, em, a, por
- definite article (o, a, os, as)
- de, em
- demonstrative (este, esse, aquele and their neuters)
- a
- distal demonstrative (aquele family only)
- de, em
- third-person pronoun (ele, ela, eles, elas)
- de
- locative adverb (aqui, aí, ali)
- de, em, a, por
Optional (both forms are correct):
- de, em
- indefinite article (dum/duma or de um/de uma)
- de, em
Never contracts (always keep separate):
- Any preposition + um, uma, uns, umas except de, em
- a
- este, esse family
- por
- anything other than a definite article
- com, sem, sob, sobre, para, entre, desde, contra
- anything
- Any preposition + mim, ti, nós, vós, si, consigo (the oblique pronouns follow their own rules — see below)
The prepositional forms of personal pronouns
A related area often confused with contraction: first- and second-person pronouns have prepositional forms used after any preposition. These are separate words, not contractions, but they are worth tabulating alongside.
| Subject | After preposition | After com (accompaniment) |
|---|---|---|
| eu | mim | comigo |
| tu | ti | contigo |
| ele / ela / você | ele / ela / si | com ele / com ela / consigo |
| nós | nós | connosco |
| vocês | vocês | convosco |
| eles / elas | eles / elas | com eles / com elas |
Connosco (PT-PT) is written with a double n, unlike Brazilian conosco. This is one of the most reliable PT-PT vs. BR spelling markers.
Queres vir connosco à festa?
Do you want to come with us to the party?
Ela disse que fala contigo amanhã.
She said she'll talk to you tomorrow.
Fica comigo mais um bocadinho.
Stay with me a little longer.
PT-PT vs. BR differences
Most of the contraction system is identical in both varieties, but a few things diverge:
- Connosco: PT-PT writes the double-n form connosco; BR writes conosco with a single n. (Convosco has the same single-n spelling in both varieties — the PT-PT vs. BR split is only on connosco.)
- Até ao / até à: PT-PT takes até with a plus the article contraction. BR usually writes até o and até a without the extra a. See the a preposition page for more.
- Indefinite article contraction: BR prose generally avoids dum, duma, num, numa, preferring de um, em um. PT-PT uses the contracted forms more freely.
- Pelas horas: PT-PT often uses pelas dez ("around ten"); BR prefers lá pelas dez or por volta das dez.
None of these are grammatical errors in either direction — they are markers of regional written style.
Quick-reference grid
If you only remember one image, make it this one. Rows are prepositions; columns are what follows.
| o, a, os, as | um, uma, uns, umas | este, esta... | esse, essa... | aquele, aquela... | isto, isso, aquilo | ele, ela, eles, elas | aqui, aí, ali | |
|---|---|---|---|---|---|---|---|---|
| de | do, da, dos, das | dum, duma (opt.) | deste, desta... | desse, dessa... | daquele, daquela... | disto, disso, daquilo | dele, dela, deles, delas | daqui, daí, dali |
| em | no, na, nos, nas | num, numa (opt.) | neste, nesta... | nesse, nessa... | naquele, naquela... | nisto, nisso, naquilo | nele, nela, neles, nelas | — |
| a | ao, à, aos, às | — | — | — | àquele, àquela... | àquilo (only) | — | — |
| por | pelo, pela, pelos, pelas | — | — | — | — | — | — | — |
A dash means: keep the preposition and the following word separate. Write a este projeto, por um motivo, por aquele caminho, em aqui → aqui (no merger needed).
Common mistakes
❌ O livro de o João está na estante.
Incorrect — de + o must contract to do.
✅ O livro do João está na estante.
João's book is on the shelf.
❌ Fiquei a casa o dia todo.
Incorrect — em + a must contract to na.
✅ Fiquei em casa o dia todo.
I stayed home all day.
❌ Chegamos a as oito.
Incorrect — a + as obligatorily contracts to às (with grave accent).
✅ Chegamos às oito.
We arrive at eight.
❌ O livro foi escrito por o autor em três meses.
Incorrect — por + o must contract to pelo.
✅ O livro foi escrito pelo autor em três meses.
The book was written by the author in three months.
❌ Referi-me a aquele senhor que estava à porta.
Incorrect — a + aquele must contract to àquele, with grave accent.
✅ Referi-me àquele senhor que estava à porta.
I was referring to that gentleman who was at the door.
❌ Ficámos a conversar até a meia-noite.
Incorrect in PT-PT — até takes a + article, giving até à.
✅ Ficámos a conversar até à meia-noite.
We stayed chatting until midnight.
❌ Vou contigo amanhã, está combinado, e depois falo com convosco sobre o plano.
Incorrect — convosco already contains com; do not write 'com convosco'.
✅ Vou contigo amanhã, e depois falo convosco sobre o plano.
I'm going with you tomorrow, and then I'll talk to you all about the plan.
❌ Fui passear conosco.
Incorrect in PT-PT — the form is connosco with double n.
✅ Fui passear connosco.
I went for a walk with us.
Key takeaways
- Four prepositions contract in European Portuguese: de, em, a, por.
- Contraction with definite articles is always obligatory — do, na, ao, pelo and their variants.
- De and em contract with almost everything: definite articles, indefinite articles (optional), all demonstratives, third-person pronouns, and (for de) locative adverbs.
- A contracts only with definite articles and the distal aquele family (always with grave accent).
- Por contracts only with definite articles.
- The grave accent on à, às, àquele, àquilo is not decorative — it is the written signal of the preposition.
- PT-PT uses connosco and convosco with double n; BR writes them with single n.
- If in doubt, contract with o/a/os/as. That rule alone catches most errors.
Related Topics
- Portuguese Prepositions OverviewA1 — Introduction to Portuguese prepositions and their uses, including the obligatory contractions that set European Portuguese apart.
- The Preposition deA1 — Uses of the preposition de — origin, possession, material, partitives, time, and the verbs that require it.
- The Preposition emA1 — Uses of the preposition em — static location, time, and state — and why Portuguese uses de (not em) for transport.
- The Preposition aA1 — Uses of the preposition a — direction, indirect objects, time, manner, and the crucial PT-PT até ao construction.
- The Preposition porA2 — Uses of the preposition por — agent, cause, means, route, duration, and its obligatory contractions pelo/pela.
- 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.