Aquest camí és llarg.

• Aquest = a demonstrative adjective, meaning this
• camí = a masculine singular noun, meaning path / road / way
• és = the 3rd person singular of ser, meaning is
• llarg = an adjective, meaning long

So the structure is:

demonstrative + noun + verb + adjective

Very similar to English: This path is long.

Because camí is masculine singular.

In Catalan, demonstratives agree with the noun in gender and number:

• aquest camí = this path
• aquesta carretera = this road
• aquests camins = these paths
• aquestes carreteres = these roads

So aquest matches camí because camí is masculine singular.

You usually learn the gender of a noun as part of the word itself. In this case, camí is masculine.

A useful clue is that you would say:

• el camí = the path

not

• la camí

So in the sentence, both aquest and llarg are masculine singular to match camí.

The accent in camí shows where the stress falls: ca-MÍ.

Without going too deep into spelling rules, the written accent tells you that the final syllable is stressed. That is important because stress in Catalan can change from word to word and is often marked in writing when needed.

So camí is pronounced roughly kah-MEE.

És with an accent is the verb is.

• és = is
• es = a different word, usually a reflexive or pronoun element, like in some verb forms

The accent helps distinguish them in writing.

So:

• Aquest camí és llarg = This path is long

Here you need és because it is the verb.

Because adjectives usually agree with the noun they describe in gender and number.

Since camí is masculine singular, the adjective is also masculine singular:

• camí llarg = long path
• carretera llarga = long road
• camins llargs = long paths
• carreteres llargues = long roads

So llarg matches camí.

Yes. In Catalan, many descriptive adjectives commonly come after the noun.

So camí llarg is the normal order for long path.

That is why the sentence is:

• Aquest camí és llarg

not a version where llarg comes before camí.

Some adjectives can appear before the noun in Catalan, but for a basic descriptive adjective like llarg, the post-noun position is the ordinary one.

No. Aquest already works directly with the noun, so you do not add the article el here.

You say:

• aquest camí = this path

not

• aquest el camí

This is similar to English: you say this path, not this the path.

A rough pronunciation for an English speaker is:

ah-KEST kah-MEE es lyark

A few important points:

• aquest: the final -t is pronounced
• camí: stress on the last syllable, ca-MÍ
• és: like ess
• llarg: the ll is traditionally a palatal sound, somewhat like the lli in million for many learners, though pronunciation varies by dialect

Also, the final g in llarg is typically pronounced like a k sound at the end because final voiced consonants are often devoiced in Catalan pronunciation.

So llarg is often heard roughly like lyark.

They refer to different distance relationships:

• aquest = this, something near the speaker
• aquell = that, something farther away

Examples:

• Aquest camí és llarg = This path is long
• Aquell camí és llarg = That path is long

In some varieties of Catalan, you may also see other demonstrative forms, but aquest and aquell are the main basic pair learners should know first.

Normally, no. A bare noun like camí usually needs some kind of determiner in a sentence like this, such as:

• Aquest camí és llarg = This path is long
• El camí és llarg = The path is long
• Un camí és llarg = A path is long

So camí és llarg by itself would not sound natural as a normal standalone sentence.

Yes.

• Aquest camí és llarg = This path is long
• El camí és llarg = The path is long

The difference is the same as in English:

• aquest points to a specific thing as this
• el just means the

So aquest is more specific in a deictic or pointing sense.

Yes, ser is the normal verb here.

Catalan, like Spanish, often distinguishes between ser and estar. With an inherent or descriptive quality like long, ser is the expected choice:

• Aquest camí és llarg = This path is long

You would not normally use estar for this kind of basic description. Long is treated as a characteristic of the path, not a temporary state.