Choose the relationship before the combined form
The preposition em often introduces location, while de can introduce origin, possession, or material. English translations vary, so do not memorize only one English word for each. Moro no Brasil says where someone lives, while Sou do Brasil says where they are from. A person can live somewhere different from their origin. First identify the relationship in the message, then decide whether the following noun phrase uses an article. Only after those choices should you combine the pieces into the written contraction.
Eu moro no Brasil.
I live in Brazil.
The verb describes residence, so the location preposition combines with the masculine article used by this country name. The resulting form expresses where the speaker lives, not where they necessarily originated.
Eu sou do Brasil.
I am from Brazil.
The sentence gives origin. The relevant preposition combines with the masculine article in this country name. The same person could currently live elsewhere without changing the origin statement.
References for this explanation
Build em with singular definite articles
The combinations are em + o = no and em + a = na. Use the article’s gender to select the form: no quarto for in the room and na escola for at or in the school. The preposition does not have gender by itself; the gender information comes from the article. The contracted forms are ordinary standard spelling, not merely casual shortcuts. Do not keep the two words separate in these simple definite article combinations. Inspect the entire noun phrase if a descriptive word or a possessive appears later.
Estou na escola.
I am at school.
The location preposition combines with the feminine singular article required by the noun in this phrase. The contraction packages two grammatical pieces into one word. It does not make the noun masculine or change the state verb.
O livro está no quarto.
The book is in the room.
The location phrase uses the masculine singular article belonging to the room noun. That article combines with the preposition. The book’s own gender is not what selects the contraction before the location noun.
Follow a complete example
Build a sentence with this meaning: I am at school. Before looking at the answer, identify which information controls the grammatical choice.
- First, identify the message: I am at school. Keep that message fixed while comparing forms. A sentence can be grammatical yet communicate something different, so meaning is part of the decision.
- The location preposition combines with the feminine singular article required by the noun in this phrase. The contraction packages two grammatical pieces into one word. It does not make the noun masculine or change the state verb.
- Now read the complete sentence, Estou na escola.. Check the words surrounding your choice as well as the choice itself. Explain what would change if the speaker, number, or intended message changed. Then cover this example and reconstruct the sentence from the English cue.
Estou na escola. I am at school.
References for this explanation
Carry plural articles into nos and nas
The plural combinations are em + os = nos and em + as = nas. The contraction reflects the number and gender of the noun phrase after it. Nos livros means in the books, while nas mesas means on the tables in a suitable context. English may use in, on, or at where Portuguese uses the same preposition. Learn the complete place expression rather than forcing every English preposition into a separate Portuguese word. The noun still needs its plural ending; the contracted article does not replace the noun’s own written number marking.
A informação está nos livros.
The information is in the books.
The location is expressed by a masculine plural noun phrase. Its article combines with the preposition to form the plural contraction. The earlier subject is singular, but it does not control the number inside this separate phrase.
Os livros estão nas mesas.
The books are on the tables.
The location phrase is feminine plural because it refers to several tables. The contraction follows that noun phrase, while the main verb agrees with the plural books. These are separate agreement relationships in one sentence.
References for this explanation
Build de for origin and possession
The singular combinations are de + o = do and de + a = da. They can connect a thing with its owner: o livro do professor or a mesa da professora. The article inside the contraction belongs to the possessor noun that follows it, not the possessed item before it. This is a common source of errors because a speaker may look at the first noun instead. Keep the relationship clear by temporarily isolating the owner phrase. The same combined forms also occur with origin and other meanings when that preposition and article meet.
É o livro da professora.
It is the female teacher’s book.
The contraction contains the feminine article associated with the owner noun. The book itself is masculine, but that earlier noun does not determine the article inside the owner phrase. Possession links two separate noun phrases.
É a mesa do professor.
It is the male teacher’s table.
The owner noun is masculine singular, so the relation preposition combines with its masculine article. The table is feminine, but its gender controls its own article rather than the later owner phrase.
References for this explanation
Make plural ownership and origin phrases
The plural combinations are de + os = dos and de + as = das. The number of owners may differ from the number of things owned: one book can belong to several students. O livro das alunas therefore has a singular possessed object and a plural possessor phrase. This is why simply making every word singular or plural together can fail. Follow each article to its own noun. A country name with a plural article also carries that article into the contraction, but learn the established country expression instead of guessing from its English translation.
É o livro das alunas.
It is the female students’ book.
The owner phrase refers to several female students, so its article is feminine plural. One shared book can still have plural owners. The contraction’s number therefore does not have to match the possessed object.
É a sala dos professores.
It is the teachers’ room, referring to male teachers or a mixed group.
The possessor noun phrase is masculine plural and takes the corresponding contraction. The room is singular feminine, but its own article has already expressed that information. The two phrases maintain separate agreement.
References for this explanation
Do not add an article to every place or expression
Contraction happens only when the article is actually present. Many city names appear directly after the preposition: em Lisboa, de São Paulo. Some place names conventionally use an article, so these examples are not a universal ban on city articles. The expression em casa commonly means at home, while na casa da Ana identifies a particular house. Material can likewise appear without an article: de madeira. Learn a place name or fixed expression together with its normal preposition phrase, and preserve the difference between a general material and an identified object.
Eu moro em Lisboa.
I live in Lisbon.
This city name normally appears without a definite article in the simple location expression. The preposition therefore remains separate and has nothing to contract with. A contraction should not invent an article merely because a place is named.
A mesa é de madeira.
The table is made of wood.
The phrase identifies material without a definite article in this ordinary construction. The preposition therefore stays in its basic form. This differs from referring to a particular identified quantity or object that might use an article.
Try the reasoning with less help
Build a sentence with this meaning: I live in Lisbon. Before looking at the answer, identify which information controls the grammatical choice.
- First, identify the message: I live in Lisbon. Keep that message fixed while comparing forms. A sentence can be grammatical yet communicate something different, so meaning is part of the decision.
- This city name normally appears without a definite article in the simple location expression. The preposition therefore remains separate and has nothing to contract with. A contraction should not invent an article merely because a place is named.
- Now read the complete sentence, Eu moro em Lisboa.. Check the words surrounding your choice as well as the choice itself. Explain what would change if the speaker, number, or intended message changed. Then cover this example and reconstruct the sentence from the English cue.
Compare your reasoning
Eu moro em Lisboa. I live in Lisbon.
References for this explanation
Recognize neighboring contractions without overgeneralizing
The location preposition can also combine with indefinite articles, giving num, numa, nuns, and numas. The separated forms em um and em uma are also possible. This differs from the definite article combinations practiced above. Other pronouns and demonstratives form additional contractions, but this lesson does not ask you to infer all of them from one table. In a complete sentence, choose the verb’s relationship, inspect the following noun phrase, and then form the contraction. Finally check number and gender against that following noun rather than an unrelated word nearby.
Estou numa escola.
I am in a school.
The location preposition combines with a feminine singular indefinite article. The phrase introduces an unspecified school rather than the definite school. The full separated version is also possible, but this exercise requests the contracted form.
Estou na casa da Ana.
I am at Ana’s house, using an article before her name.
The prompt explicitly uses the feminine article before the personal name, so the possession preposition contracts with it. Brazilian usage of articles before names varies; the grammatical choice here follows the stated noun phrase rather than a universal name rule.
References for this explanation
Notice the difference
Common mistakes
Follow the location noun
Instead ofEstou no escola.
For this meaningEstou na escola.
The location noun is feminine, so the article inside the contraction must be feminine. The preposition itself does not carry gender independently. Identify the noun following the contraction and retrieve its article before combining the pieces. This is a noun phrase agreement problem, not a change to the verb.
Follow the owner noun
Instead ofo livro do professora
For this meaningo livro da professora
The owner noun is feminine. Its article determines the contraction in the possession phrase, even though the possessed book is masculine. Keep the two noun phrases separate while checking agreement. A single sentence can contain several articles with different genders because each belongs to its own noun.
Do not invent an article
Instead ofMoro na Lisboa.
For this meaningMoro em Lisboa.
This ordinary city expression uses the preposition directly without an article. A contraction is possible only when its component article is part of the intended phrase. Other place names can behave differently, so learn each name in a complete location and origin expression rather than assuming that all cities share one pattern.
From understanding to using
Make your own example.
Try these without answer choices. Say your answer aloud or write it below, then compare your reasoning with the model.
Your turn 1
Say that you are from Brazil but live in Lisbon.
Compare with a model
Sou do Brasil, mas moro em Lisboa.
I am from Brazil, but I live in Lisbon.
The first phrase gives origin and combines its preposition with the article conventionally used by the country name. The second gives residence, and this city expression uses no article to combine. The contrast shows two independent decisions: which relationship the preposition expresses and whether the following name takes an article. Do not choose the contraction before deciding both.
- Did you preserve the requested meaning?
- Does the form match the person or noun in your message?
- Can you explain your choice before looking at the model?
Your turn 2
Say that the male teacher’s table is in the female students’ room.
Compare with a model
A mesa do professor está na sala das alunas.
The male teacher’s table is in the female students’ room.
Each contraction belongs to the noun phrase immediately after it. The first identifies a masculine singular owner, the second a feminine singular location, and the third feminine plural owners of that location. The table’s own gender does not control all three. Break the sentence into these relationships, then rebuild it without the model and explain each article inside its contraction.
- Did you preserve the requested meaning?
- Does the form match the person or noun in your message?
- Can you explain your choice before looking at the model?
Put it into practice
Make the next choice.
Choose a response and learn why it works. Your score reflects your first answer to each question. You can revisit anything you miss.
Choose an answer, then open the explanation to check your reasoning.
Question 1
Complete the sentence for this meaning: I live in Brazil.
Eu moro ___ Brasil.
- no
- do
Check the answer
Answer: no
no: The verb describes residence, so the location preposition combines with the masculine article used by this country name. The resulting form expresses where the speaker lives, not where they necessarily originated.
do: This combines the origin or relation preposition with the article. It does not fit the ordinary residence construction requested here.
Question 2
Complete the sentence for this meaning: I am from Brazil.
Eu sou ___ Brasil.
- no
- do
Check the answer
Answer: do
no: This is the location contraction. It does not express the ordinary origin relationship in this sentence.
do: The sentence gives origin. The relevant preposition combines with the masculine article in this country name. The same person could currently live elsewhere without changing the origin statement.
Question 3
Complete the sentence for this meaning: I am at school.
Estou ___ escola.
- na
- no
Check the answer
Answer: na
na: The location preposition combines with the feminine singular article required by the noun in this phrase. The contraction packages two grammatical pieces into one word. It does not make the noun masculine or change the state verb.
no: This includes a masculine article. The noun in the phrase is feminine and requires the corresponding contraction.
Question 4
Complete the sentence for this meaning: The book is in the room.
O livro está ___ quarto.
- na
- no
Check the answer
Answer: no
na: This would contain a feminine article. The contraction must agree with the room noun that follows it, not another noun earlier in the sentence.
no: The location phrase uses the masculine singular article belonging to the room noun. That article combines with the preposition. The book’s own gender is not what selects the contraction before the location noun.
Question 5
Complete the sentence for this meaning: The information is in the books.
A informação está ___ livros.
- nos
- no
Check the answer
Answer: nos
nos: The location is expressed by a masculine plural noun phrase. Its article combines with the preposition to form the plural contraction. The earlier subject is singular, but it does not control the number inside this separate phrase.
no: This contains a singular article. The location noun is plural and requires its matching plural form.
Question 6
Complete the sentence for this meaning: The books are on the tables.
Os livros estão ___ mesas.
- nos
- nas
Check the answer
Answer: nas
nos: This contains a masculine plural article. The location noun is feminine, so the masculine form does not fit.
nas: The location phrase is feminine plural because it refers to several tables. The contraction follows that noun phrase, while the main verb agrees with the plural books. These are separate agreement relationships in one sentence.
Question 7
Complete the sentence for this meaning: It is the female teacher’s book.
É o livro ___ professora.
- da
- do
Check the answer
Answer: da
da: The contraction contains the feminine article associated with the owner noun. The book itself is masculine, but that earlier noun does not determine the article inside the owner phrase. Possession links two separate noun phrases.
do: This contains a masculine article for the possessor. The specified owner noun is feminine and requires the other form.
Question 8
Complete the sentence for this meaning: It is the male teacher’s table.
É a mesa ___ professor.
- da
- do
Check the answer
Answer: do
da: This incorrectly follows the table’s gender instead of the owner noun’s gender. The contraction belongs with the noun immediately after it.
do: The owner noun is masculine singular, so the relation preposition combines with its masculine article. The table is feminine, but its gender controls its own article rather than the later owner phrase.
Question 9
Complete the sentence for this meaning: It is the female students’ book.
É o livro ___ alunas.
- das
- da
Check the answer
Answer: das
das: The owner phrase refers to several female students, so its article is feminine plural. One shared book can still have plural owners. The contraction’s number therefore does not have to match the possessed object.
da: This contains a singular article. It does not match the plural owner noun supplied by the sentence.
Question 10
Complete the sentence for this meaning: It is the teachers’ room, referring to male teachers or a mixed group.
É a sala ___ professores.
- do
- dos
Check the answer
Answer: dos
do: This is singular. The owner phrase is plural and requires its plural article inside the contraction.
dos: The possessor noun phrase is masculine plural and takes the corresponding contraction. The room is singular feminine, but its own article has already expressed that information. The two phrases maintain separate agreement.
Question 11
Complete the sentence for this meaning: I live in Lisbon.
Eu moro ___ Lisboa.
- em
- na
Check the answer
Answer: em
em: This city name normally appears without a definite article in the simple location expression. The preposition therefore remains separate and has nothing to contract with. A contraction should not invent an article merely because a place is named.
na: This would introduce a feminine article that the ordinary city phrase here does not use. Learn the established expression rather than forcing contraction everywhere.
Question 12
Complete the sentence for this meaning: The table is made of wood.
A mesa é ___ madeira.
- da
- de
Check the answer
Answer: de
da: This contains a definite article and would require a different identified reference. It does not express the neutral material description requested here.
de: The phrase identifies material without a definite article in this ordinary construction. The preposition therefore stays in its basic form. This differs from referring to a particular identified quantity or object that might use an article.
Question 13
Complete the sentence for this meaning: I am in a school.
Estou ___ escola.
- numa
- num
Check the answer
Answer: numa
numa: The location preposition combines with a feminine singular indefinite article. The phrase introduces an unspecified school rather than the definite school. The full separated version is also possible, but this exercise requests the contracted form.
num: This contains a masculine indefinite article. The noun is feminine and requires the feminine contraction.
Question 14
Complete the sentence for this meaning: I am at Ana’s house, using an article before her name.
Estou na casa ___ Ana.
- do
- da
Check the answer
Answer: da
do: This contains a masculine article and does not fit the feminine name phrase specified by the prompt.
da: The prompt explicitly uses the feminine article before the personal name, so the possession preposition contracts with it. Brazilian usage of articles before names varies; the grammatical choice here follows the stated noun phrase rather than a universal name rule.
Keep the conversation going
What to practice next
Return to the production tasks after a break. Reconstruct your sentences without the models, compare the meaning and form, and repair any error by explaining its cause. Then use one sentence in a short exchange of your own.
Sources and editorial notes
By Loquus ·
Source checked with AI assistance
These original explanations synthesize the cited sources. They have not been certified by an independent human language specialist. Regional usage and context are described where they affect the answer. Report a correction in the discussion below.
- Dicionário Priberam: em
- Dicionário Priberam: de
- Dicionário Priberam: no
- Dicionário Priberam: na
- Dicionário Priberam: do
- Dicionário Priberam: da
- University of Texas, Tá Falado grammar lesson 2: Contractions
- Dicionário Priberam: morar
- Dicionário Priberam: Present conjugation of morar
- University of Washington, Bate Papo: University life
- Ricardo Aragón and Steel Wagstaff: Lição 1
- Dicionário Priberam: artigo
Learning research behind the practice
Worked examples, retrieval practice, and later review inform the activities. These studies do not establish the effectiveness of this specific lesson.
- Karpicke and Roediger: The critical importance of retrieval for learning
- Butler and Roediger: Feedback enhances the positive effects and reduces the negative effects of multiple choice testing
- Institute of Education Sciences: Organizing Instruction and Study to Improve Student Learning
- Rittle Johnson and Star: Compared to what?