Prepositions and contractions

A preposition is an invariable word that links two elements of a sentence, subordinating one to the other: between them it sets up a relation of place, time, cause, purpose, possession, company or material. It belongs to a closed class — no new prepositions are coined — yet it includes some of the most frequent and grammatically dense words in the language. In Portuguese it carries two notable peculiarities: it governs the form of whatever follows it (its government), and it fuses phonetically with the next word in a rich system of contractions.

The inventory

The so-called simple (or essential) prepositions are few and very old, inherited wholesale from Latin:

a, ante, após, até, com, contra, de, desde, em, entre, para, perante, por, sem, sob, sobre, trás.

To these are added accidental prepositions — words from other classes pressed into prepositional service (conforme “according to”, durante “during”, exceto “except”, mediante “by means of”, salvo “save”, segundo “according to”) — and prepositional phrases, fixed groups ending in a preposition: antes de “before”, depois de “after”, através de “through”, acerca de “concerning”, em vez de “instead of”, por causa de “because of”, perto de “near”.

The four most used — a, de, em, por — are also those that pile up the most meanings. De, for instance, expresses origin (venho de Lisboa “I come from Lisbon”), possession (o livro de Ana “Ana’s book”), material (uma estátua de pedra “a stone statue”), cause (morrer de fome “to die of hunger”) and topic (falámos de política “we talked about politics”), among many other values.

Government: the preposition the verb requires

Many verbs, nouns and adjectives demand a fixed preposition to introduce their complement. This bond is called government (regência): it is not free, it forms part of the word’s meaning, and it must be learnt case by case. Swapping it sounds wrong or changes the sense.

Verbal government is one of the points where European and Brazilian Portuguese diverge most, especially with verbs of motion and everyday use.

Nouns and adjectives often inherit the government of the related verb: o gosto pela música “the taste for music”, a necessidade de ajuda “the need for help”, fiel a alguém “faithful to someone”, capaz de tudo “capable of anything”, contente com o resultado “pleased with the result”.

The contractions

The most visible mark of the Portuguese prepositional system is the contraction: the obligatory fusion of certain prepositions with a following article, demonstrative or pronoun. Four prepositions contract with the definite article:

	o	a	os	as
de	do	da	dos	das
em	no	na	nos	nas
a	ao	à	aos	às
por	pelo	pela	pelos	pelas

De and em also contract with the indefinite article (dum, duma, num, numa), with the demonstratives (deste, desse, daquele; neste, nisto, naquilo), with personal pronouns (dele, dela, neles) and with some adverbs (daqui, daí, dali, donde). The preposition a contracts with the demonstratives beginning in a-: àquele, àquela, àquilo.

The case of à: contraction and crase

The form à results from the preposition a plus the feminine article a (a + a = à). The grave accent does not mark stress: it signals crase, the fusion of two identical vowels into one. In European Portuguese this fusion has a phonetic reflex: the plain preposition-and-article a is pronounced reduced, [ɐ] , whereas the contraction à keeps the open vowel, [a] .

Com and the pronominal forms

The preposition com “with” does not contract with the article, but it merges with the stressed personal pronouns into special forms inherited from Latin: comigo “with me”, contigo “with you”, consigo “with him/her/oneself”, connosco “with us”, convosco “with you (pl.)”. They are obligatory — there is no *com mim or *com nós.

Easily confused

The boundary between por que, porque, porquê and por quê, or between the preposition a and the verb form há “there is/ago”, is a constant source of hesitation. One should also keep a fim de “in order to” apart from afim “akin”, and de encontro a “into collision with” from ao encontro de “to meet, in favour of”. In all these cases the preposition — unstressed and almost effaced in speech — calls for special care in writing.

For the contractions with the article seen from the article’s own side, see Articles and contractions; for nominal government and agreement, see Agreement and government.