La cambra d'aire és buida.

Literally, cambra d'aire means chamber of air.

Grammatically, it is made of:

• cambra = chamber
• d'aire = of air

So the main noun is cambra, and d'aire specifies what kind of chamber it is.

In Catalan, this kind of noun + de + noun structure is very common. In English, we often translate it more naturally as a compound noun, such as air chamber or sometimes inner tube, depending on context.

Because de is shortened before a word that begins with a vowel. This is called elision.

So:

• de + aire → d'aire

This happens very often in Catalan:

• d'aigua = of water
• d'or = of gold
• d'hivern = of winter

So d'aire is just the normal Catalan form.

In a fixed expression like cambra d'aire, Catalan normally uses de without an article.

So:

• cambra d'aire = the normal compound expression

If you said cambra de l'aire, it would sound more like chamber of the air, which is a different, more literal idea and not the usual phrase here.

This is similar to how English often says air chamber, not the air's chamber.

És is the 3rd person singular of ser: is.

The accent is important because it distinguishes és from es:

• és = is
• es = an unstressed pronoun, like oneself / himself / itself in some contexts

So in this sentence, és means is.

Because the adjective must agree with the noun.

Here, cambra is:

• feminine
• singular

So the adjective must also be feminine singular:

• buit = masculine singular
• buida = feminine singular
• buits = masculine plural
• buides = feminine plural

Since the noun is la cambra, the correct form is buida.

You can tell from the article:

• la cambra

The article la marks it as feminine singular.

Also, many Catalan nouns ending in -a are feminine, though there are exceptions. In this sentence, the article makes it completely clear.

Because buida is not directly modifying the noun inside the noun phrase. It is a predicate adjective after the verb és.

The structure is:

• La cambra d'aire = subject
• és = verb
• buida = adjective describing the subject

This is similar to English:

• The air chamber is empty

Not:

• The empty is air chamber

If you want to describe the noun directly, Catalan can place the adjective after the noun:

• la cambra buida = the empty chamber

But in your sentence, the verb és makes buida part of the predicate.

Yes, and in many everyday situations that may even sound more natural if you mean it is currently empty.

A useful rough guide is:

• ser = identity, classification, description
• estar = state or condition

So:

• és buida can sound like a more neutral description
• està buida emphasizes the present state: it is empty right now

In real Catalan, ser and estar can overlap, and usage can vary by dialect and context. If you are talking about something that currently has no air in it, many speakers would naturally use està buida.

Yes, if you mean the specific air chamber.

• La cambra d'aire és buida. = The air chamber is empty.

Without the article, Cambra d'aire és buida would not sound like normal standard Catalan in an ordinary sentence. It might only appear in very special styles such as headlines, labels, or notes.

So in normal speech and writing, la is the expected form.

A broad pronunciation guide is:

la KAHM-bra DAI-ra ez BWEE-da

A few useful notes:

• cambra: stress on the first syllable
• aire: sounds roughly like AI-ra
• és: a short stressed ez
• buida: the bui- part sounds roughly like bwee-

Pronunciation varies somewhat by dialect, but that approximation will help you say it understandably.