La vàlvula és aquí.

La is the feminine singular definite article in Catalan, equivalent to the.

• la vàlvula = the valve
• una vàlvula = a valve

Catalan often uses articles in the same kinds of places English does, so if English has the valve, Catalan normally has la vàlvula.

You usually learn the noun together with its article: la vàlvula.

In this sentence, the article la tells you the noun is feminine singular. Also, many nouns ending in -a are feminine in Catalan, though that is a pattern, not an absolute rule.

Because vàlvula is feminine singular, anything agreeing with it would also need feminine singular forms where relevant.

És is the 3rd person singular form of ser, meaning is.

So:

• jo sóc = I am
• tu ets = you are
• ell/ella és = he/she/it is

Since the subject is la vàlvula (a singular noun), Catalan uses és.

This is a very common question, because Catalan has both ser and estar.

In a sentence like La vàlvula és aquí, Catalan commonly uses ser to indicate location, especially in straightforward identification or placement statements.

So for basic location:

• És aquí = It is here

English speakers often expect a distinction like Spanish, but Catalan does not use estar in exactly the same way Spanish does. In many ordinary location sentences, ser is perfectly normal.

The grave accent in vàlvula shows where the stress falls.

It is pronounced with the stress on the first syllable:

• VÀL-vu-la

Without getting too technical, the accent helps you know that the word is not stressed later in the word.

The accent in és helps distinguish it from es.

• és = is
• es = a reflexive or unstressed pronoun, depending on context

So the accent is important both for pronunciation and for meaning.

Aquí is stressed on the last syllable because of the accent:

• a-QUÍ

A rough English-friendly guide would be something like ah-KEE.

The accent marks the stress clearly.

Yes, Catalan word order can be flexible, and Aquí és la vàlvula can be possible depending on emphasis.

Compare:

• La vàlvula és aquí. → neutral statement about where the valve is
• Aquí és la vàlvula. → stronger emphasis on here

That said, La vàlvula és aquí is the most straightforward and neutral version.

Aquí is the standard word for here.

Catalan also has ací in some varieties, but aquí is the form learners will most often see and use.

So for general learning purposes:

• aquí = here

No. Catalan does not require a separate subject pronoun here because the noun itself is already the subject:

• La vàlvula = the subject
• és = is
• aquí = here

So La vàlvula és aquí is complete as it stands.

You put no before the verb:

• La vàlvula no és aquí.

That is the normal way to say The valve is not here.

In Catalan, you can often make a yes/no question just by using question intonation in speech, or question marks in writing:

• La vàlvula és aquí?

You may also see more explicit question structures in other contexts, but this is the simplest direct way.

The structure is:

• La vàlvula = subject
• és = verb
• aquí = adverb of place

So it follows a very familiar pattern:

subject + verb + place

That makes it a very beginner-friendly Catalan sentence.