de + um = dum
Contraction Dum
de + um = dum
Meaning: 'of a', 'from a', or 'of one'.
How It Works
The contraction dum is formed by dropping the final '-e' of the preposition de and joining it with um.
Key Usage Rules:
- Gender and Number: It changes based on the noun it precedes: dum (masc. sing.), duma (fem. sing.), duns (masc. plural), and dumas (fem. plural).
- Optionality: Unlike 'do' (de + o), which is mandatory, dum is technically optional. You can say de um or dum. However, dum is very common in spoken Portuguese and in European Portuguese writing.
- Regional Differences: In Portugal, dum is standard in all registers. In Brazil, it is used constantly in speech, but writers often prefer the uncontracted de um in formal documents.
- The Infinitive Exception: You cannot use the contraction if the word um is the subject of an infinitive verb. For example: 'O fato de um aluno chegar...' (The fact of a student arriving...).
Examples (5)
- Eu gosto muito dum bolo que a minha avó faz.
I really like a cake that my grandmother makes.
Word by Word: I like much of-a cake that the my grandmother makes.
The verb gostar requires the preposition 'de', which here contracts with 'um bolo'.
- Ele precisa dum favor teu.
He needs a favor from you.
Word by Word: He needs of-a favor yours.
The verb 'precisar' (to need) takes the preposition 'de', resulting in the contraction 'dum'.
- Votos dum feliz Natal para todos!
Wishes for a Merry Christmas to everyone!
Word by Word: Wishes of-a happy Christmas for all!
This is a common formal or semi-formal greeting where 'de' and 'um' are contracted.
- Ela é filha duma amiga minha.
She is the daughter of a friend of mine.
Word by Word: She is daughter of-a friend mine.
This shows the feminine version 'duma' (de + uma).
- Eu vim duns lugares muito bonitos.
I came from some very beautiful places.
Word by Word: I came from-some places very beautiful.
This shows the plural version 'duns' (de + uns).
Common Mistakes
Using an archaic apostrophe.
Eu preciso d'um café.Eu preciso dum café.In modern Portuguese, the apostrophe is no longer used for this contraction. Write it as one single word.
Contracting before an infinitive subject.
Antes dum homem falar, ele deve pensar.Antes de um homem falar, ele deve pensar.When 'um' is the subject of an infinitive verb (falar), you must keep 'de' and 'um' separate.
Confusing 'dum' with 'num'.
Eu moro dum apartamento pequeno.Eu moro num apartamento pequeno.Use 'num' (em + um) for location (in a). Use 'dum' (de + um) for origin or possession (of/from a).
How It Connects
Learn This First
To understand the contraction 'dum', you need to be familiar with its two component parts: the preposition 'de' and the masculine indefinite article 'um'. It is also helpful to have already encountered the concept of contractions in Portuguese, such as 'do' (de + o).
- um/uma/uns/umasIndefinite Articles
The learner must be familiar with the indefinite article 'um' as it is the second component of this contraction.
Foundations - de + o = doContraction Do
Understanding the concept of preposition-article contractions through the more common definite article forms provides the necessary conceptual framework for indefinite contractions.
Level 1
Related Patterns
- de + uma = dumaContraction Duma
The feminine singular version of this contraction.
Level 2 - em + um = numContraction Num
A similar contraction using the preposition 'em' (in/on) instead of 'de'.
Level 1 - a/de/em/com/para/porBasic Prepositions
The basic prepositions that frequently form contractions in Portuguese.
Foundations
Words in This Pattern
Practice de + um = dum in Bubblegum
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