Introduction
Understanding result clauses is essential for clear communication in Portuguese. This article explains how to use two common connectors, portanto and por isso, to express results and consequences in Brazilian Portuguese. You will learn the grammar rules, position in a sentence, subtle differences in meaning and register, and see many real-life examples to build confidence.
- What are result clauses?
- Portanto: formal and concise
- Por isso: neutral and conversational
- Portanto vs por isso: differences and overlap
- Other result connectors to know
- Placement patterns and examples
- Common mistakes and how to avoid them
- Stylistic tips and cultural notes
- Combining connectors with other sentence elements
- Quick reference summary
- Conclusion
What are result clauses?
Result clauses show the consequence or outcome of an action or situation. In English, they often translate as therefore, so, thus, or because of that. In Portuguese, connectors like portanto and por isso are used to link cause and effect. These connectors help listeners understand why something happened or what follows from a previous statement.
Basic structure
A simple pattern for a result clause is:
Cause + connector + Result
Example:
Não estudei para a prova, portanto tirei uma nota baixa.
Portanto: formal and concise
Portanto is a formal connector used to introduce a logical conclusion or consequence. It functions similarly to therefore or thus in English. It is often found in written language, formal speech, and structured arguments. Use portanto when you want to sound more formal or academic.
Grammar and punctuation with portanto
Portanto is usually preceded by a comma when it connects two independent clauses. It can appear at the beginning, middle, or end of a sentence, but the most common positions are between clauses or at the very beginning of the second clause.
Examples:
Ele não fez a lição, portanto não entende o assunto.
O restaurante estava fechado.
Portanto, tivemos que procurar outro lugar.
Estudou muito;
portanto, passou no exame.
Verb tense and agreement
Portanto does not change verb tense or mood by itself. The tense and mood of the verb in the result clause depend on the time and certainty of the result.
Present result:
Ela mora longe, portanto demora para chegar.
Past result:
A chuva começou cedo, portanto cancelaram o evento.
Conditional or future contexts:
Se você economizar,
portanto poderá viajar no próximo ano.
When to prefer portanto
Use portanto in formal writing, academic texts, presentations, or when you want to emphasize a logical conclusion. It is less common in casual spoken Brazilian Portuguese, where speakers often use more conversational connectors.
Por isso: neutral and conversational
Por isso is very common in spoken Brazilian Portuguese and is a neutral way to express consequence. It is equivalent to so, because of that, or for that reason. Use por isso in everyday conversations, emails to friends, and many informal contexts.
Grammar and punctuation with por isso
Por isso usually appears between clauses and is commonly followed by a comma when connecting two independent clauses. Because it is a two-word phrase, it can be more flexible in speech and often replaces portanto in casual settings.
Examples:
Choveu muito,
por isso o jogo foi adiado.
Ele está doente;
por isso não veio hoje.
Quero aprender português,
por isso faço aulas duas vezes por semana.
Pronoun placement and por isso
When the result clause contains object pronouns, normal placement rules apply within that clause. Por isso does not affect pronoun placement, but the speaker may choose different verb forms or pronouns depending on register.
Example with direct object pronoun:
O professor explicou bem,
por isso eu entendi a matéria.
Portanto vs por isso: differences and overlap
Both portanto and por isso express consequences, but they have subtle differences in formality, rhythm, and emphasis.
Formality
Portanto is more formal and commonly used in written texts or formal speech. Por isso is more neutral or informal and frequent in spoken language.
Rhythm and emphasis
Portanto is a single word and often creates a compact, punchy transition between ideas. Por isso is more conversational and can sound softer or more natural in dialogue.
Flexibility and combinations
Sometimes the choice is simply about sound and rhythm rather than strict grammar. You can often replace one with the other without changing the meaning, but your register may shift.
Interchangeable examples:
Não paguei a conta,
portanto não posso voltar lá hoje.
Não paguei a conta,
por isso não posso voltar lá hoje.
Other result connectors to know
Portuguese has several connectors for result and consequence; knowing them helps you vary your language and choose appropriate register.
Common alternatives:
então — casual, similar to so
assim — neutral, can be formal or informal, similar to thus
logo — slightly formal, close to therefore
consequentemente — formal, often used in written or academic contexts
Examples with então and assim:
Estava tarde,
então pegamos um ônibus.
Ele não estudou,
assim falhou no teste.
Placement patterns and examples
Result connectors can appear in different positions. Below are common patterns with examples so you can recognize and use them naturally.
Between two independent clauses
Cause, connector, result.
Example with por isso:
O trânsito estava ruim,
por isso cheguei atrasado.
At the beginning of the result clause
Connector + result clause.
Example with portanto:
Estudou muito.
Portanto, merece a promoção.
Within a longer sentence
You can use connectors inside a complex sentence with subordinate clauses.
Example:
Como não havia sinalização adequada,
portanto a obra atrasou e causou transtornos no trânsito.
Common mistakes and how to avoid them
Beginners often make mistakes with punctuation, register, or redundancy. Here are typical errors and simple fixes.
Punctuation
Do not forget the comma before the connector when it separates independent clauses. The comma clarifies the boundary between cause and result.
Incorrect: Eu não comprei o ingresso portanto não entrei.
Correct: Eu não comprei o ingresso,
portanto não entrei.
Redundancy
Avoid using two connectors back-to-back; it sounds repetitive. Choose one connector to express the result.
Incorrect: Estava chovendo,
por isso, portanto, cancelaram o passeio.
Correct: Estava chovendo,
por isso cancelaram o passeio.
Wrong register
Match the connector to the situation. Using portanto in a casual chat can sound stiff, while using por isso in a formal paper may be too relaxed.
Casual chat: Então, vamos sair hoje? or Por isso não fui.
Formal writing: Portanto, os resultados sugerem que…
Stylistic tips and cultural notes
Brazilian Portuguese favors natural, conversational connectors in daily speech. Speakers commonly use então and por isso in informal contexts. In written or formal contexts, especially academic or legal texts, portanto, logo, and consequentemente are preferred.
Brazilian speakers also like rhythm and clarity. Short sentences connected by por isso or então often sound more fluent in conversation. In presentations, using portanto can make your conclusions sound more authoritative.
Register examples
Informal conversation:
Não tenho dinheiro,
então vou ficar em casa hoje.
Formal report:
Os dados mostram uma tendência negativa;
portanto, é necessário revisar a estratégia.
Combining connectors with other sentence elements
You can combine result connectors with adverbs, subordinate clauses, and modal verbs to express nuances such as probability, necessity, or intention.
Probability:
Ele não atende o telefone,
por isso provavelmente está ocupado.
Necessity:
Choveu muito,
portanto precisamos adiar a viagem.
Intention or plan:
Quero melhorar meu português,
por isso vou praticar todos os dias.
Quick reference summary
Use this short guide to choose a connector quickly.
Portanto: formal, written, logical conclusion.
Example: Estudou muito, portanto passou.
Por isso: neutral, conversational, common in speech.
Example: Estava cansado, por isso não fui à festa.
Also consider então, assim, logo, and consequentemente depending on register.
Conclusion
Mastering result clauses with portanto and por isso helps you express consequences clearly and appropriately in Brazilian Portuguese. Remember that portanto is more formal and concise, while por isso is neutral and frequent in conversation. Learn the punctuation rules, pay attention to register, and practice with real sentences to build fluency.
