Você se lembra de onde está a chave?

Because lembrar-se is a very common way to say to remember in Portuguese.

So:

• lembrar-se de algo = to remember something
• Você se lembra...? = Do you remember...?

The se is not really translated word-for-word into English here. It is just part of how this verb is often used.

In everyday Brazilian Portuguese, many people also say Você lembra...? without se, especially in casual speech.

Because the full pattern is lembrar-se de.

So Portuguese says:

• lembrar-se de uma coisa
• lembrar-se de um nome
• lembrar-se de onde...

That is why you get:

• Você se lembra de onde está a chave?

If you keep se, the de is normally expected.

Yes. That is very common in Brazil.

There are a few patterns you may hear:

• Você se lembra de onde está a chave? — more complete/careful
• Você lembra onde está a chave? — very common in everyday speech
• Você lembra de onde está a chave? — also heard in colloquial Brazilian Portuguese

For a learner, você se lembra de... is a safe structure to know well.

Because onde is used for location, while aonde is used with movement toward a place.

Here the question is about where the key is, not where it is going.

So:

• Onde está a chave? = location
• Aonde você vai? = movement

Since the key is just located somewhere, onde is correct.

Because estar is used for location.

When you ask where something is physically located, Portuguese normally uses estar:

• A chave está na mesa.
• Onde está a chave?

Using ser here would be wrong, because ser is not the normal verb for the location of objects.

Portuguese usually keeps the normal question-style order after onde:

• onde está a chave

This sounds natural and standard.

An English speaker may expect something like onde a chave está because English says where the key is, but that order sounds less natural in Portuguese and can feel marked or influenced by English.

So the most natural version is:

• Você se lembra de onde está a chave?

You can leave it out in many situations, especially in speech, if the context is clear.

For example:

• Se lembra de onde está a chave?
• Lembra de onde está a chave?

Both are common in informal Brazilian Portuguese.

Still, você is often included for clarity, emphasis, or just because the speaker wants to be explicit.

In most of Brazil, você is the normal everyday way to say you. It is usually neutral, not especially formal.

More formal options would be:

• O senhor se lembra...?
• A senhora se lembra...?

In some regions, people use tu instead of você, but the exact verb forms can vary a lot in real speech.

Because Portuguese usually uses the definite article with a specific noun.

Here a chave means the key — a specific key that both people know about.

So:

• a chave = the key
• uma chave = a key

Leaving out the article here would sound unnatural in normal Portuguese.

A very natural spoken version might be:

• Cê lembra onde tá a chave?

Here is what changed:

• você → cê
• está → tá
• sometimes se and de get dropped in casual speech

So you may hear several real-life versions, such as:

• Você se lembra de onde está a chave?
• Você lembra onde está a chave?
• Cê lembra onde tá a chave?

All of these can sound natural, depending on the situation and level of formality.