B1 · Intermediate Chapter 5

Expressing Cause, Path, and Rate with 'Por'

6 Total Rules
62 examples
5 min
Rules in This Chapter Quick Practice

Chapter in 30 Seconds

Master 'Por' to explain the 'why', 'how', and 'where' of your Portuguese journey.

  • Express the cause or reason behind any action or emotion.
  • Describe movement through spaces and the methods used to communicate.
  • Calculate rates, prices, and time durations accurately.
Connect your thoughts with the power of 'Por'.

What You'll Learn

Hey, ready to level up your Portuguese? This chapter is all about 'Por' – that little word with HUGE power! You'll stop just getting by and start explaining things like a pro. Ever wondered how to say *why* something happened, or that you walked *through* a beautiful park? What about how much something costs *per* kilo, or that you studied *for* hours? 'Por' is your answer to all of these! We'll dive into its six main roles: explaining the *cause* or *reason* behind actions, describing *movement through a space* (like

walking along the river
), identifying the *means* or *method* of an action (sent by mail), and even talking about *rates* and *durations* of time (working per day). By understanding how 'por' connects these ideas – cause, path, method, rate, time – you'll unlock a whole new layer of expression. You'll master nuanced differences between 'por' and 'para', helping you avoid common mistakes intermediate learners make. After this, you'll effortlessly chat about *why* you love Portuguese, *how* you learned it, and *for how long* you've been practicing, making your conversations much more natural and engaging. Get ready to sound truly B1!

Learning Objectives

By the end of this chapter, you will be able to:

  1. 1
    By the end you will be able to explain the reason for an action using 'por causa de' or 'por' + noun.
  2. 2
    By the end you will be able to navigate a city by describing paths 'through' or 'along' specific landmarks.
  3. 3
    By the end you will be able to discuss prices per unit and frequency of habits per time period.

Chapter Guide

Overview

Hey there, language learners! Ready to unlock a super versatile and incredibly common word in Portuguese grammar? This chapter is all about 'Por' – a tiny preposition with immense power that's absolutely crucial for reaching a B1 Portuguese level and beyond. Mastering 'Por' will significantly boost your ability to express complex ideas, making your conversations much more natural and precise. You'll stop just translating word-for-word and start thinking like a native speaker. We'll explore how 'Por' helps you explain *why* something happened, describe *movement through a space*, identify the *means* or *method* of an action, and even talk about *rates* and *durations* of time. By the end of this guide, you’ll effortlessly differentiate 'Por' from its sometimes-confusing cousin, 'Para', avoiding common intermediate mistakes and truly sounding like a pro. Get ready to express cause, path, and rate with confidence!

How This Grammar Works

The preposition 'Por' is a workhorse in Portuguese, connecting ideas in numerous ways. Let's break down its key functions, which are essential for any B1 Portuguese speaker.
First, 'Por' is fundamental for Expressing Cause & Reason. It tells us *why* something happens or *because of what*.
* Ele fez isso por amor. (He did that out of love.)
* A reunião foi adiada por causa da chuva. (The meeting was postponed because of the rain.)
Next, it's used for Expressing Cause, Exchange & Path. While cause is covered above, 'Por' also indicates exchange (like trading one thing for another) and movement along or through a path.
* Troquei meu carro por uma moto. (I exchanged my car for a motorcycle.)
* Caminhamos pela floresta. (We walked through the forest.) – Note pela is por + a.
This leads us to Portuguese Prepositions: Through and Along (Por). It describes movement *through* or *along* a place.
* Passamos por Lisboa. (We passed through Lisbon.)
* Andei pelo parque. (I walked through/along the park.) – Again, pelo is por + o.
'Por' is also vital for Means, Methods, and Agents. It specifies *how* an action is performed or *by whom* (in passive sentences).
* Enviei a carta por correio. (I sent the letter by mail.)
* O livro foi escrito por um autor famoso. (The book was written by a famous author.)
When talking about quantities or frequencies, we use 'Por' for Saying 'Per' or 'By': Rates with Por.
* Custa dez euros por quilo. (It costs ten euros per kilo.)
* Trabalho oito horas por dia. (I work eight hours per day.)
Finally, Por for Time (Duration & Approximation) indicates a duration of time or an approximate period.
* Estudei por três horas. (I studied for three hours.)
* Ele virá por volta das cinco. (He will come around five o'clock.)
Mastering these uses of 'Por' will significantly enhance your understanding of Portuguese grammar and your ability to communicate effectively.

Common Mistakes

  1. 1✗ Wrong: Fiz o trabalho para meu amigo. (I did the work for my friend.)
✓ Correct: Fiz o trabalho por meu amigo. (I did the work for my friend – *meaning on behalf of/instead of him*)
*Explanation:* While para often means "for" (purpose, destination), por is used when you do something *on behalf of* someone, or *in exchange for* them. If you did the work *for* your friend *so they could have it*, you might use para. But if you did it *because your friend couldn't*, por is correct.
  1. 1✗ Wrong: Viajamos para o trem. (We traveled to the train.)
✓ Correct: Viajamos de trem. (We traveled by train.) OR Viajamos por trem. (Less common, but still means by train).
*Explanation:* When referring to the means of transportation, de is most common. However, por can also be used for means/method, especially in more formal contexts or when emphasizing the *channel* through which something occurs. Para indicates destination, not the means of travel itself.
  1. 1✗ Wrong: Estudei para cinco horas. (I studied for five hours.)
✓ Correct: Estudei por cinco horas. (I studied for five hours.)
*Explanation:* To express a duration of time, por is the correct preposition. Para implies a purpose or destination, not how long an action lasted.

Real Conversations

A

A

Por que você está tão feliz hoje? (Why are you so happy today?)
B

B

Estou feliz por ter passado no exame! (I'm happy because I passed the exam!)
A

A

Você prefere viajar de carro ou por trem? (Do you prefer to travel by car or by train?)
B

B

Prefiro ir por avião, é mais rápido. (I prefer to go by plane, it's faster.)
A

A

A encomenda chegou por correio ou por uma transportadora? (Did the package arrive by mail or by a shipping company?)
B

B

Chegou por uma transportadora, foi entregue por um motorista. (It arrived by a shipping company, it was delivered by a driver.)

Quick FAQ

Q

What's the main difference between por and para when expressing purpose?

Para typically expresses purpose or destination ("for the sake of," "to"), while por implies cause, reason, or exchange ("because of," "on behalf of," "in exchange for").

Q

Can por always be replaced by pelo/pela?

Pelo (por + o) and pela (por + a) are contractions of por with definite articles. They are used when por is followed by a masculine or feminine singular noun, respectively. So, no, por isn't *always* replaced; it depends on whether an article follows.

Q

How do native speakers use por to talk about approximate time?

They often use phrases like por volta de (around/approximately) or simply por followed by a general time period, like por estes dias (around these days).

Cultural Context

In everyday Portuguese, 'Por' is incredibly common and often used fluidly. Native speakers might sometimes use 'por' in ways that seem subtle to learners, especially in idiomatic expressions. For instance, "obrigado por..." (thank you *for*...) is a fixed expression using por to indicate the reason for gratitude. While regional accents and common phrases vary, the core grammatical functions of 'por' remain consistent across Brazil and Portugal, making it universally understood and essential for authentic communication.

Key Examples (8)

1

Obrigado por me ajudar com a mudança.

Thanks for helping me with the move.

Portuguese Preposition 'Por': Expressing Cause & Reason
2

Ela não foi trabalhar pelo cansaço.

She didn't go to work because of the tiredness.

Portuguese Preposition 'Por': Expressing Cause & Reason
3

Eu paguei uma fortuna pelo novo iPhone.

I paid a fortune for the new iPhone.

Preposition Por: Expressing Cause, Exchange & Path
4

Vamos passar pelo parque para chegar mais cedo.

Let's go through the park to arrive earlier.

Preposition Por: Expressing Cause, Exchange & Path
5

Eu caminhei pelo parque hoje de manhã.

I walked through the park this morning.

Portuguese Prepositions: Through and Along (Por)
6

Ela gosta de correr pela praia ao pôr do sol.

She likes to run along the beach at sunset.

Portuguese Prepositions: Through and Along (Por)
7

Mandei a foto pelo WhatsApp.

I sent the photo via WhatsApp.

Portuguese Preposition 'Por': Means, Methods, and Agents
8

O vídeo foi editado pela Maria.

The video was edited by Maria.

Portuguese Preposition 'Por': Means, Methods, and Agents

Tips & Tricks (4)

💡

The 'Para' Test

If you can replace it with 'in order to', use 'para'. If not, use 'por'.
frontend.learn_grammar.from_rule: Portuguese Preposition 'Por': Expressing Cause & Reason
💡

Check the article

Whenever you see 'por' followed by 'o', 'a', 'os', or 'as', always contract it!
frontend.learn_grammar.from_rule: Preposition Por: Expressing Cause, Exchange & Path
💡

Contractions are mandatory

Never write 'por o' or 'por a'. Always use 'pelo' or 'pela'.
frontend.learn_grammar.from_rule: Portuguese Prepositions: Through and Along (Por)
💡

Contractions are key

Always look for the article after 'por'. If it's 'o', 'a', 'os', or 'as', contract it!
frontend.learn_grammar.from_rule: Portuguese Preposition 'Por': Means, Methods, and Agents

Key Vocabulary (7)

motivo reason troca exchange caminho path/way correio mail quilo kilogram durante during (often synonymous with por in time) através through

Real-World Preview

shopping-cart

At the Local Market

clock

Explaining a Delay

Review Summary

  • Verbo + por + Substantivo
  • Verbo de Movimento + pelo/pela + Local
  • Número + por + Unidade

Common Mistakes

Use 'para' for purpose (to do something) and 'por' for cause. Since seeing birds is the goal/purpose, 'para' is required.

Wrong: Vou para o parque por ver os pássaros.
Correct: Vou ao parque para ver os pássaros.

In Portuguese, 'por' must contract with definite articles. 'Por' + 'a' always becomes 'pela'.

Wrong: Eu ando por a rua.
Correct: Eu ando pela rua.

In passive voice, the agent (the person doing the action) is introduced by 'por', not 'para'.

Wrong: O livro foi escrito para Machado de Assis.
Correct: O livro foi escrito por Machado de Assis.

Next Steps

You've just unlocked one of the most versatile tools in the Portuguese language. Your ability to explain reasons and paths will make your conversations much more fluid. Keep practicing those contractions!

Narrate your walk to work/school using 'pelo/pela'.

Look at a grocery receipt and state prices 'por quilo'.

Continue to: Nuanced Comparisons and Passive Actions

Quick Practice (10)

Select the correct preposition.

Vou ___ casa.

✓ Correct! ✗ Not quite. Correct answer: para
Destination requires 'para'.

frontend.learn_grammar.from_rule: Portuguese Preposition 'Por': Means, Methods, and Agents

Select the best option.

Eu ___ por muito tempo.

✓ Correct! ✗ Not quite. Correct answer: todas
All work with 'por'.

frontend.learn_grammar.from_rule: Por for Time (Duration & Approximation)

Select the correct contraction.

Passamos ___ rua.

✓ Correct! ✗ Not quite. Correct answer: pela
Contraction of 'por' + 'a'.

frontend.learn_grammar.from_rule: Portuguese Preposition 'Por': Means, Methods, and Agents

Fill in the blank.

O projeto foi aprovado ___ diretoria.

✓ Correct! ✗ Not quite. Correct answer: pela
Diretoria is feminine.

frontend.learn_grammar.from_rule: Portuguese Prepositions: Through and Along (Por)

Choose the correct sentence.

Which is correct?

✓ Correct! ✗ Not quite. Correct answer: Custa 5 pelo quilo
Por + o = pelo.

frontend.learn_grammar.from_rule: Saying 'Per' or 'By': Rates with Por (por dia, pelo quilo)

Fill in the blank with the correct contraction.

Caminhei ___ (por + a) rua.

✓ Correct! ✗ Not quite. Correct answer: pela
Por + a = pela.

frontend.learn_grammar.from_rule: Preposition Por: Expressing Cause, Exchange & Path

Choose the correct sentence.

Which is correct?

✓ Correct! ✗ Not quite. Correct answer: Chego por volta das 8.
Requires 'das' or 'de'.

frontend.learn_grammar.from_rule: Por for Time (Duration & Approximation)

Fill in the blank.

___ que você não veio?

✓ Correct! ✗ Not quite. Correct answer: Por que
Question uses 'Por que'.

frontend.learn_grammar.from_rule: Portuguese Preposition 'Por': Expressing Cause & Reason

Fix the sentence.

Find and fix the mistake:

Eu trabalho para hora.

✓ Correct! ✗ Not quite. Correct answer: Eu trabalho por hora
Rate requires por.

frontend.learn_grammar.from_rule: Saying 'Per' or 'By': Rates with Por (por dia, pelo quilo)

Select the correct preposition.

Ele foi elogiado ___ professor.

✓ Correct! ✗ Not quite. Correct answer: pelo
Contraction 'pelo' (por + o).

frontend.learn_grammar.from_rule: Portuguese Preposition 'Por': Expressing Cause & Reason

Score: /10

Common Questions (6)

No, use 'para' for destination. 'Por' is for cause or movement through.
In Portuguese, 'por' contracts with articles for better flow.
Usually, yes. You can also use 'por causa de', but 'por' is more concise.
Yes, for duration (e.g., 'por duas horas').
Use 'pelo' when 'por' is followed by the masculine article 'o'. It is a mandatory contraction.
It is common, but in informal Brazilian Portuguese, it is often omitted.
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The Rules of Pronoun Placement
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Nuanced Comparisons and Passive Actions
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