Learn Hardcore Portuguese (Brazil): Quando a porta está aberta, o corredor parece maior. - When the door is open, the hallway seems bigger.

In Brazilian Portuguese, when you talk about something that happens regularly or whenever a condition is true, you normally use the present indicative after quando:

Quando a porta está aberta, o corredor parece maior.
= Whenever the door is open, the hallway seems bigger.

Even if in English you might think of this as something that could happen in the future, Portuguese still uses the present to express general truths or habitual situations.

A true future idea is usually expressed with the future subjunctive:

Quando a porta estiver aberta, o corredor vai parecer maior.
= When the door is open (at that future moment), the hallway will seem bigger.

So:

está → habitual/general situation.
estiver → specific future situation, often with vai, irá, etc.

What is the difference between quando a porta está aberta and quando a porta estiver aberta?

Both are grammatically correct but have different nuances:

Quando a porta está aberta, o corredor parece maior.
Talks about a general rule or habit. Every time the door is in the state of being open, the hallway seems bigger. Very neutral, everyday statement.
Quando a porta estiver aberta, o corredor vai parecer maior.
Focuses on a future moment or event. This is like saying: “At the time when the door gets to be open (in the future), the hallway will seem bigger.”

In many everyday situations, Brazilians prefer the simple present (está) for general truths like this sentence.

Why is it está aberta and not é aberta?

Portuguese distinguishes between ser and estar:

estar is used for temporary states or conditions.
ser is used for permanent characteristics or for passive constructions (actions done to something).

In this sentence, aberta describes a temporary state of the door:

A porta está aberta. = The door is open (right now / in that situation).

If you say:

A porta é aberta às 8 horas.

This sounds like a passive voice action: “The door is opened at 8 o’clock (by someone).” That’s about a scheduled action, not its current state.

So here we want a state → está aberta is correct.

Why is it aberta and not aberto?

In Portuguese, adjectives (and many past participles used as adjectives) agree in gender and number with the noun they describe.

porta is feminine singular → a porta.
So the adjective/participle must also be feminine singular → aberta.

Forms:

aberto – masculine singular
aberta – feminine singular
abertos – masculine plural
abertas – feminine plural

Examples:

O portão está aberto. (masculine singular)
As portas estão abertas. (feminine plural)

Could I say abrida instead of aberta?

No. The verb abrir has an irregular past participle:

abrir → aberto (masc.), aberta (fem.)

There is a regular form abrido, but in modern Portuguese it is practically never used in normal speech, and abrida sounds wrong in this context.

For the idea “open” as a state, always use aberto/aberta/abertos/abertas, not abrido/abrida.

Why do we say a porta and o corredor with articles? Can I drop the article?

Portuguese uses definite articles (o, a, os, as) more often than English uses the.

In this sentence, we are talking about a specific door and a specific hallway, so the natural form is:

Quando a porta está aberta, o corredor parece maior.

If you say:

Quando porta está aberta, corredor parece maior.

that sounds very wrong/unnatural in Portuguese; it’s missing the articles.

In general, use the article when referring to a specific, known thing:

a porta = the door
o corredor = the hallway

What exactly does corredor mean here, and are there other meanings?

In this sentence, corredor means hall or hallway (like in a house, apartment, or building).

But corredor has other common meanings in Portuguese:

runner (a person who runs)
- Ele é um corredor profissional. = He is a professional runner.
corridor in the sense of a passage between areas (also in politics: corredor de exportação, etc.)

Context tells you which meaning is intended. Here, with porta and maior, it clearly means hallway.

Why is the adjective maior placed after corredor? Could it go before?

By default, in Portuguese, adjectives usually come after the noun:

o corredor maior = the bigger hallway

In the sentence:

o corredor parece maior

maior is not directly next to the noun, because it’s part of the predicate, but it still describes corredor and follows the usual pattern: noun first, then adjective.

You could put some adjectives before the noun to add stylistic, emotional, or special emphasis, but:

maior corredor usually suggests “the greatest/best corridor (in some sense)” rather than just “physically bigger hallway.”

So for neutral size comparison, corredor maior (or parece maior) is the natural choice.

What’s the difference between maior and mais grande?

Maior is the irregular comparative of grande and is the normal, natural way to say bigger or larger.

grande → maior (bigger)
pequeno → menor (smaller)

So you say:

O corredor parece maior. = The hallway seems bigger.

Mais grande is grammatically possible but sounds strange or childish in standard speech. Use maior, not mais grande, in normal Portuguese.

What does parece mean here? Is it more like “seems” or “looks”?

The verb parecer means both to seem and to look/appear (in the sense of “to seem”).

So:

O corredor parece maior.

can be understood as:

“The hallway seems bigger.”
or
“The hallway looks bigger.”

English has two common verbs (seem, look) for this idea; Portuguese usually uses just parecer for both.

Can I change the word order to O corredor parece maior quando a porta está aberta?

Yes, absolutely. Both orders are natural:

Quando a porta está aberta, o corredor parece maior.
O corredor parece maior quando a porta está aberta.

The meaning is essentially the same. Starting with Quando a porta está aberta slightly emphasizes the condition first (“when the door is open…”). Starting with O corredor emphasizes the hallway first.

In speech, Brazilians easily use both structures.

What is the difference between quando and se in a sentence like this?

Both can introduce a condition, but they carry different nuances:

Quando a porta está aberta, o corredor parece maior.
= When/whenever the door is open, the hallway seems bigger.
Implies that this condition does happen, and it’s more like a general rule.
Se a porta estiver aberta, o corredor vai parecer maior.
= If the door is open, the hallway will seem bigger.
Here, it’s more hypothetical: the door may or may not be open.

In your original sentence, quando is perfect because it talks about a regular, recurring situation, not a mere possibility.

How do you pronounce quando a porta está aberta, o corredor parece maior in Brazilian Portuguese?

Approximate pronunciation (Brazilian):

Quando → /ˈkwɐ̃.du/
- qu like kw, ã is a nasal “uh” sound.
a → /a/ (short ah)
porta → /ˈpɔɾ.tɐ/
- or like “or” in British “port,” ɾ is a quick flap (like the American English “tt” in “water”).
está → /es.ˈta/
- Stress on -tá.
aberta → /a.ˈbɛɾ.tɐ/
- é like “e” in “bed”.
o → /u/ (often sounds like oo in “food” when unstressed).
corredor → /ko.ʁe.ˈdoʁ/
- Brazilian r can sound like an English h or French r in some regions.
parece → /pa.ˈɾɛ.si/
maior → /ma.ˈjɔʁ/
- Sounds roughly like “ma-YOR,” with ai like “eye”.

Spoken naturally, many words link smoothly: Quando a porta está aberta, o corredor parece maior.