Necessito una fotocòpia més abans que comenci la classe.

In Catalan, subject pronouns are often left out because the verb ending already shows who the subject is.

• necessito = I need
• necessites = you need
• necessita = he/she/it needs

So Necessito una fotocòpia més is perfectly natural. You can say Jo necessito... if you want extra emphasis, contrast, or clarity, but it is not usually necessary.

It means one more photocopy.

The structure is:

• una fotocòpia = a photocopy
• més = more

So:

• una fotocòpia més = one more photocopy
• dues fotocòpies més = two more photocopies

This is a very common Catalan pattern: noun + més.

Because in Catalan, when you mean another / one more / additional, més usually comes after the noun or quantity.

Examples:

• un minut més = one more minute
• una pregunta més = one more question
• tres dies més = three more days

This is different from English, where more often comes before the noun.

Yes, and it is very natural.

There is a small nuance:

• una fotocòpia més = one more photocopy
• una altra fotocòpia = another photocopy

In many everyday situations, they are very close in meaning.
However, una fotocòpia més emphasizes the idea of an additional one, while una altra fotocòpia can sound a bit more like another one.

Both are correct.

Because abans que is used when it is followed by a conjugated verb:

• abans que comenci la classe = before the class starts

By contrast, abans de is used before an infinitive:

• abans de començar la classe = before starting class

So the choice depends on the structure:

• abans que + conjugated verb
• abans de + infinitive

Because after abans que, Catalan normally uses the subjunctive, especially when talking about something that has not happened yet.

So:

• abans que comenci la classe = before the class starts

Here, the class has not started yet, so Catalan uses the subjunctive comenci, not the indicative comença.

This is a very important pattern:

• abans que + subjunctive

Comenci is the present subjunctive form of començar (to begin / to start), for ell/ella/vostè.

Relevant forms:

• jo comenci
• tu comencis
• ell/ella comenci
• nosaltres comencem
• vosaltres comenceu
• ells/elles comencin

In this sentence, the subject is la classe, which is singular, so Catalan uses the third person singular form: comenci.

This is a spelling change to preserve pronunciation.

The verb is començar, but in some forms the spelling changes:

• començo
• comences
• comença
• comenci
• comencin

Catalan changes the spelling so the sound stays correct before different vowels.

A learner does not need to memorize all the spelling rules at once, but it is useful to recognize that this kind of spelling change is normal in Catalan verbs.

Catalan uses the definite article more often than English.

So:

• la classe = the class

Even where English might say before class, Catalan often says abans que comenci la classe or abans de la classe, depending on the structure.

Using the article here is completely natural.

In this sentence, classe means the lesson / class session.

So comenci la classe means:

• the class begins
• the lesson starts

Depending on context, classe can also refer to a school class in a broader sense, but here it clearly means the session that is about to begin.

A useful approximate pronunciation for an English speaker is:

• fo-to-KO-pi-a

The stressed syllable is cò.

Also notice the written accent:

• fotocòpia

That accent helps show where the stress falls.

Yes, Necessito is completely natural and straightforward.

Catalan also has other ways to express need, such as em cal, but necessitar is very common and easy to use.

So for a learner, this sentence is a very good model:

• Necessito una fotocòpia més... = I need one more photocopy...

Yes, but the structure would change.

Original:

• Necessito una fotocòpia més abans que comenci la classe.

Possible rewrite:

• Necessito una fotocòpia més abans de començar la classe.

The second version means before starting class and uses abans de + infinitive.

The difference is subtle:

• abans que comenci la classe focuses on the class beginning
• abans de començar la classe uses an infinitive structure, more like before starting class

Both can be correct depending on the exact meaning you want.