Por Isso vs. Por Causa de: Result and Cause in Portuguese — Practice

Use por isso to state the result

Por isso means “that is why” or “because of that.” It points back to information already given and introduces the consequence that follows.

The phrase is useful at the beginning or middle of a sentence. A comma often marks a pause when por isso starts a new clause.

Use por causa de to name the cause

Por causa de means “because of” and introduces the reason or circumstance that caused something. Before a masculine singular noun, de + o contracts to do; before a feminine singular noun, de + a becomes da.

The phrase can also appear before plural nouns: por causa dos horários (because of the schedules) and por causa das obras (because of the construction).

Connect one cause and one result

You can express the same relationship with both structures: a cause with por causa de, followed by a result with por isso. This is useful when you want to make the logic easy to follow.

Because por causa de is followed by a noun phrase, use porque before a full clause with its own verb. Compare por causa da chuva and porque estava chovendo.

Remember: Por causa de introduces a reason; por isso introduces what happened as a result. Use porque before a clause with a verb.

Check your understanding

Choose the English meaning of each Portuguese example. Answer before looking back at the tables. These questions check the written examples in this guide; they are not a listening or proficiency test.

Recall the Portuguese, then say it

Read the English prompt and say a Portuguese version before opening the answer. The answer shows the example from the lesson; other natural translations may also work. Compare the meaning and the situation rather than counting a different word as automatically wrong.

1. The bus was late; that’s why we arrived after eight.

   Show a Portuguese answer

   O ônibus atrasou; por isso, chegamos depois das oito.

2. She works near home and, because of that, walks there.

   Show a Portuguese answer

   Ela trabalha perto de casa e, por isso, vai a pé.

3. I don’t know the area. That’s why I’ll use the map.

   Show a Portuguese answer

   Não conheço a região. Por isso, vou usar o mapa.

4. The flight was delayed because of the bad weather.

   Show a Portuguese answer

   O voo atrasou por causa do mau tempo.

5. The street was closed because of the market.

   Show a Portuguese answer

   A rua ficou fechada por causa da feira.

6. We changed the time because of the children.

   Show a Portuguese answer

   Mudamos o horário por causa das crianças.

Make the phrase useful to you

Choose one example you could actually use. Say it once from memory, then change one detail that fits your life, such as the person, place, time, or object. Check whether your change also needs a different verb form, article, or adjective ending. If it does, compare it with the pattern in the explanation.

Por causa de introduces a reason; por isso introduces what happened as a result. Use porque before a clause with a verb.

Return to two prompts tomorrow without opening the answers first. If a phrase still feels difficult, shorten it to a useful chunk and build the complete sentence again.

Sources and your next lesson

This I Speak Portuguese practice guide builds on our Por Isso vs. Por Causa de: Result and Cause in Portuguese lesson on Real Life Portuguese, with written recall tasks and additional speaking practice. The explanations and examples are teaching material; the practice questions are exercises, not a transcript of a recording.

To add Brazilian audio to your routine, choose a lesson in the Real Life Portuguese app. The app offers its own lessons and practice; this page does not imply that every example here has an app recording.