“Durante” vs “Por” in Portuguese: Duration and Time Periods

Introduction

Understanding how to express time and duration is essential for communicating clearly in Portuguese. Two words that often confuse learners are durante and por. Both can relate to time, but they function differently and appear in different contexts. This article explains the rules, shows natural Brazilian Portuguese examples, and provides usage tips so you can choose the right word every time.

Overview: durante and por

Durante and por both connect actions to periods of time, but they have distinct meanings and grammatical patterns. Durante usually indicates a continuous span in which something happens, emphasizing the overlapping of an event with a time period. Por, when related to time, often emphasizes duration as a measure or indicates a reason or exchange in other contexts. We’ll focus mainly on time-related uses of por.

Key difference in one sentence

Durante = while/throughout a specific period.
Por = for a measured length of time (sometimes interchangeable with while, depending on context).

How durante works

Durante is a preposition used to indicate that something occurs throughout a specified period. It pairs naturally with nouns that denote a time span such as horas, dias, semanas, meses, anos, manhã, tarde, noite, festa, viagem, reunião, etc.

Structure and examples

Structure: durante + definite time period or event

Examples:

Eu estudei durante a noite.
Nós conversamos durante a viagem.
Ela dormiu durante três horas.
As crianças brincaram durante a festa.

In these examples durante highlights that the action took place across the entire time span mentioned or at least overlapped significantly with it. Using durante suggests continuity or presence within that period.

When to prefer durante

Use durante when you want to stress that an activity happened at some point or throughout a defined period. It works well with named events and general time-of-day phrases:

durante o verão, durante a aula, durante a viagem, durante o show, durante a noite

Note that durante is never used directly with verbs; it attaches to nouns describing time or events.

How por works when expressing duration

Por is more versatile and can express duration with a focus on the length of time. When used for duration, it typically pairs with a time expression introduced by a number or a quantified period.

Structure and examples

Structure: por + time period (usually without article) or por + infinitive in some contexts

Examples:

Eu fiquei aqui por duas horas.
Ela viajou por um mês.
Ele trabalhou por três anos naquela empresa.
Vou ficar por mais uma semana.

In these sentences por quantifies the duration — it tells how long the action lasted or will last. Por tends to appear when the number or measurement of time is explicit.

Por vs durante with numbers

When a numeric measure is present, both words can sometimes be used, but the nuance changes. Compare:

Eu estudei durante três horas. (I studied during/throughout three hours — emphasis on the period studied.)
Eu estudei por três horas. (I studied for three hours — emphasis on the total length of study.)

Both are grammatically correct. Native speakers often prefer por to express total duration and durante to emphasize the overlap with a particular time period or event. In practice, the distinction is subtle and context-dependent.

Comparing examples side-by-side

Look at these pairs to see how meaning shifts based on subtle emphasis:

Trabalhei durante o dia. (I worked during the day — focus on working across the daytime period.)
Trabalhei por dez horas. (I worked for ten hours — focus on the number of hours worked.)

Ela telefonou durante a reunião. (She called during the meeting — emphasis that the call occurred within the meeting.)
Ela telefonou por cinco minutos. (She called for five minutes — emphasis on the call’s length.)

When they are interchangeable

There are many contexts where both durante and por are possible without changing the core meaning, especially with simple time spans:

Eu dormi durante duas horas. / Eu dormi por duas horas.

The choice often comes down to style and emphasis. Durante may sound slightly more formal or descriptive, while por is direct and common in everyday speech.

Cases where they are not interchangeable

Despite overlap, there are contexts where substitution is incorrect or awkward.

Durante required

When linking actions to named events or broader periods, durante is the natural choice.

Durante a pandemia, muitas pessoas trabalharam de casa. (Correct)
Por a pandemia, muitas pessoas trabalharam de casa. (Incorrect)

Notice that por cannot replace durante when referring to an event or named period without restructuring the sentence to use por causa de or similar.

Por required

When expressing reason or exchange, por is necessary and unrelated to temporal duration.

Comprou o presente por R$50. (for/exchange) — durante cannot be used here.
Ele foi preso por roubo. (for/because of) — durante cannot replace por.

Also, when giving precise measured durations with numbers, por is often more natural in spoken Portuguese.

Other time-related uses of por

Por has several non-duration uses that learners should know so they do not confuse contexts.

Por can indicate reason: Ele foi elogiado por sua coragem.
Por can indicate movement through space or time: Andamos por toda a cidade.
Por can appear in fixed expressions about frequency: Três vezes por semana.
Por can form passive-agent constructions: O livro foi escrito por ela.

Be attentive: when you see por it might not be talking about duration at all, so parse the sentence for context.

Practical tips and native usage notes

1. If you can rephrase the sentence in English as while or during a named event, durante is likely the best choice.
2. If you can rephrase the sentence as for X hours/days/weeks, por is often the natural option.
3. With numbers and measurements, learners will hear por more often in spoken Brazilian Portuguese.
4. Use durante with general time-of-day expressions: durante a manhã, durante a noite.
5. Avoid mixing meanings: por can mean because of or in exchange, which durante never does. For reasons, use por causa de or por alone depending on structure.

Colloquial contractions and spoken forms

In casual speech, prepositions can contract or be omitted depending on rhythm. For example, você pode ouvir pessoas saying Fiquei lá duas horas instead of Fiquei lá por duas horas — the por is often omitted in everyday conversation. However, in writing or careful speech, include the preposition.

Examples in longer sentences

Durante as férias, nós exploramos várias cidades do Nordeste e provamos comidas típicas.
Ficamos no Rio por cinco dias e conseguimos ver praias famosas e museus.
Durante o show, a banda tocou todas as músicas do novo álbum.
Eles moraram em São Paulo por sete anos antes de se mudar para o exterior.

Common mistakes to avoid

1. Using durante to express reason or exchange: Ela fez isso durante amor is incorrect — use por or por causa de for reasons.
2. Forgetting articles with durante: Use durante + definite period when appropriate: durante a aula, durante o dia. When using numbers, either is possible: durante três horas or por três horas.
3. Overusing one preposition: Listen to native usage and vary according to nuance — both words are useful for different emphases.

Mini glossary: quick reference

Durante — during, throughout; used with named periods and events; emphasizes overlap.
Por — for; used to indicate measured duration, reason, exchange, frequency, movement, or agent in passives.

Conclusion

Both durante and por are essential for expressing time in Portuguese, but they serve different functions. Use durante to emphasize that an action took place within or throughout a specific period or event. Use por when specifying the length of time, and for many non-temporal meanings such as reason, exchange, or frequency. Listening to natural Brazilian Portuguese will help you internalize the subtle differences and use each preposition confidently.