How do Portuguese contractions like do and na work?
Portuguese fuses prepositions with the articles and demonstratives that follow them, and the fusion is compulsory rather than optional. De plus o becomes do, em plus a becomes na, a plus o becomes ao. The accented à is the same fusion of a plus a, marked with a grave accent because the two vowels collapse into one sound.
The core contractions
Four prepositions — de, em, a and por — contract with the definite articles. These appear in almost every sentence, so they need to be automatic rather than derived each time.
de + o = do, de + a = da
of the / from the
em + o = no, em + a = na
in the / on the
a + o = ao, a + a = à
to the
por + o = pelo, por + a = pela
by the / through the
They contract with demonstratives too
The same prepositions fuse with este, esse and aquele, which produces forms that look unfamiliar but follow the identical pattern.
de + este = deste
of this
em + esse = nesse
in that
a + aquele = àquele
to that one
The accent marks the collapsed vowels.
de + ele = dele
his / of him
Also used for possession.
Crasis — the à
When the preposition a meets the feminine article a, the two merge into a single à. The accent is not decorative: it distinguishes vou a Lisboa from vou à praia, and getting it wrong is a genuine written error.
Vou à praia.
I'm going to the beach.
a + a = à.
Vou a Lisboa.
I'm going to Lisbon.
City names usually take no article, so no crasis.
às três horas
at three o'clock
Plural crasis.
Common mistakes
Vou a a praia.
Vou à praia.
The contraction is compulsory, and the merged form takes the grave accent.
O livro de o professor
O livro do professor
De plus o always contracts. Writing them separately is not an option.
Falo de ele.
Falo dele.
De contracts with pronouns as well as articles.
Frequently asked questions
Are contractions optional?
No. Unlike English, where cannot and can't are both acceptable, Portuguese contractions are obligatory in both speech and writing. De o is simply not written.
How do I know when to use crasis?
It happens when the preposition a meets a feminine noun that takes an article. A rough test: if you can substitute a masculine noun and get ao, then the feminine takes à.
Do Brazil and Portugal contract the same way?
Yes — this is shared ground. Some preferences about whether a particular noun takes an article differ, which can change whether crasis appears, but the mechanism is identical.