“Algum” vs “Nenhum” in Portuguese: Positive and Negative Sentences

Introduction

Learning how to use algum and nenhum is essential for forming positive and negative sentences in Brazilian Portuguese. These words look similar but follow specific rules depending on negation, noun gender and number, and context. This article explains when to use each, shows clear examples in Brazilian Portuguese, and highlights common pitfalls for English-speaking learners.

Overview: what are algum and nenhum?

Algum and nenhum are determiners used to express indefiniteness in Portuguese. They correspond roughly to English some/any and none/not any. Their form changes to agree with the noun they modify: gender and number matter. Understanding how negation interacts with these words is the key to using them correctly.

Forms and agreement

The basic forms in Brazilian Portuguese are:

Algum (masculine singular)
Alguma (feminine singular)
Alguns (masculine plural)
Algumas (feminine plural)

Nenhum (masculine singular)
Nenhuma (feminine singular)
Nenhum does not commonly have plural forms when used with the standard negation pattern; instead, the singular is used to express no/not any.
Nenhuma (feminine singular)

Unlike English,Portuguese usually keeps nenhum and nenhuma in the singular even when speaking of more than one item, because negation is expressed by the determiner rather than by a plural form.

Positive sentences: using algum

Use algum when the sentence is affirmative and you want to indicate an unspecified quantity (some, any in positive contexts). It often suggests that at least one exists or is available, but without specifying exactly which one.

Simple affirmative examples

Quando você quer indicar a presença de algo de forma vaga:

Eu tenho algum dinheiro.
Ela trouxe algumas flores para a festa.
Você conhece alguns restaurantes bons aqui?

With questions

In questions, algum often translates to English any or some depending on whether the speaker expects a positive answer.

Você tem algum problema?
Precisa de alguma ajuda?

These questions are open-ended; the speaker does not assume a negative.

With verbs and infinitives

Algum can modify nouns after verbs or with infinitives:

Quero comprar algum presente para minha mãe.
Eles precisam de algumas informações antes de viajar.

Negative sentences: using nenhum

Use nenhum when the sentence is negative and you want to say none or not any. In Portuguese, negation is typically formed with não + determiner, and nenhum replaces what would be algum in an affirmative sentence.

Standard negative structure

The basic pattern is: não + verb + nenhum + noun. Portuguese often requires the negation particle não, and nenhum alone does not create a negative sentence without não in many contexts.

Eu não tenho nenhum dinheiro.
Ela não trouxe nenhuma flor para a festa.
Nós não vimos nenhum problema.

Why use não with nenhum?

Portuguese grammar typically uses double negation: a negative word like nenhum co-occurs with não. This is a grammatical requirement, unlike in English where double negatives are often avoided. If you omit não and only use nenhum as the determiner, the sentence may sound incomplete or change meaning.

Incorrect: Tenho nenhum dinheiro.
Correct: Não tenho nenhum dinheiro.

Differences from English negation

English uses some in positive sentences and any in negative sentences or questions. Portuguese uses algum for positive and nenhum for negative, but you still need não for negation. This leads to double negative forms that are correct and standard in Portuguese.

English vs Portuguese examples

English: I don’t have any money.
Portuguese: Não tenho nenhum dinheiro.

English: Do you have any questions?
Portuguese: Você tem alguma pergunta?

Note how questions in Portuguese can use algum if you expect a positive answer, while negative statements require nenhum plus não.

Special cases and nuances

Using nenhum alone for emphasis

In spoken Brazilian Portuguese, people sometimes use nenhum without an explicit não in short answers or fragmentary speech for emphasis. This is more colloquial and the meaning is still negative because context provides the negation.

Você viu alguém? — Nenhum.
Here the response implies Não vi ninguém, but the short form is understood.

Negative pronouns: ninguém and nada

Remember that nenhum is a determiner for nouns. For people and things as pronouns, Portuguese uses different words: ninguém for nobody/no one and nada for nothing. These also use não in more complex sentences.

Não vi ninguém na festa.
Não encontrei nada interessante.

Plural contexts and style

Although nenhum is commonly singular, you will sometimes hear plural forms like nenhuns and nenhumas in regional or informal speech, but they are less standard. For clear, formal usage, prefer the singular nenhum/nenhuma even when referring to multiple items.

Common mistakes and how to avoid them

English speakers often make predictable errors when learning these words. Here are common mistakes and corrections.

Omitting não in negative sentences

Incorrect: Tenho nenhum amigo no Brasil.
Correct: Não tenho nenhum amigo no Brasil.

Always include não for full negative sentences unless using short, colloquial replies where context implies negation.

Using algum in negative sentences

Incorrect: Não tenho algum tempo.
Correct: Não tenho nenhum tempo.
In negative contexts, replace algum with nenhum.

Agreement errors

Remember to match gender and number for algum and nenhum with the noun they modify.

Incorrect: Não vi nenhuma cachorro.
Correct: Não vi nenhum cachorro. or Não vi nenhum cachorro. (masculine noun with masculine determiner)

Contextual and cultural usage notes

Brazilian Portuguese speakers often use informal shortcuts in speech. For example, you might hear nada and ninguém used alone as answers, or abbreviated forms like tô sem nenhum in very casual contexts. These forms are fine in conversation but avoid them in formal writing.

Politeness and softening statements

When you want to soften a refusal or negative statement, Portuguese speakers might choose indirect constructions rather than a direct não + nenhum. For instance, to decline help politely, you can use a softer phrase:

Obrigado, mas não preciso de ajuda agora.
This avoids a strong-sounding Não tenho nenhum… and sounds more polite.

Regional variations

Brazil is large and diverse. In some regions, colloquial speech prefers shorter negations or different pronoun usage. However, the grammar rules for algum and nenhum remain consistent across regions in formal contexts.

Putting it all together: examples and translations

Here is a set of paired examples to illustrate the contrast between affirmative and negative sentences.

Affirmative: Eu tenho algum tempo hoje.
Negative: Não tenho nenhum tempo hoje.

Affirmative: Ela encontrou algumas respostas no relatório.
Negative: Ela não encontrou nenhuma resposta no relatório.

Affirmative question: Você tem alguma sugestão?
Negative statement: Não tenho nenhuma sugestão para oferecer.

Affirmative: Compramos alguns ingressos para o show.
Negative: Não compramos nenhum ingresso para o show.

Quick reference: when to use each

Use algum (alguma/alguns/algumas) when the sentence is positive or when asking a question expecting a positive answer.
Use nenhum (nenhuma) with não to form negative sentences meaning none or not any.
Remember to match gender and, for algum, number with the noun. Prefer singular nenhum/nenhuma for standard negation.

Conclusion

Mastering algum versus nenhum helps you form clear and natural sentences in Brazilian Portuguese. Use algum in affirmative contexts and questions that expect yes, and use nenhum with não to express negation. Pay attention to gender agreement and the common practice of double negation with não. With these rules and the example sentences above, you will avoid common errors and communicate more confidently.