L'actor diu que encara ha d'assajar perquè el públic d'aquesta funció és exigent.

In Catalan, the masculine singular article el usually drops its vowel before a word beginning with a vowel or mute h. So:

el + actor → l'actor

This is called elision. You will also see the same pattern in words like l'amic and l'hotel.

Catalan often leaves out subject pronouns because the verb form already tells you the person. Here, diu means he/she says, so ell is not necessary.

You could say L'actor diu... or Ell diu..., but adding ell would usually give extra emphasis or contrast.

Diu is the 3rd person singular present of dir (to say), and que introduces the clause that follows it.

So diu que... means says that...

Catalan normally keeps que in this kind of sentence, even where English sometimes drops that:

• He says that he still has to rehearse
• Catalan: Diu que encara ha d'assajar

Here encara means still.

So encara ha d'assajar means he still has to rehearse.

Depending on context, encara can also have other meanings, such as yet or even, but in this sentence still is the natural meaning.

This is the Catalan structure haver de + infinitive, which expresses obligation or necessity.

• ha de = has to
• assajar = to rehearse

So ha d'assajar means has to rehearse.

The apostrophe appears because de becomes d' before a vowel:

• de + assajar → d'assajar

This haver de structure is the normal standard way to express have to / must in Catalan.

Because perquè written as one word means because.

That is exactly what is needed here: ...perquè el públic... és exigent = ...because the audience is demanding

By contrast, per què as two words usually means why or for what in questions or indirect questions:

• Per què estudies català? = Why are you studying Catalan?

So in this sentence, perquè is the correct form.

Públic is a collective noun, like audience in English. Even though it refers to a group of people, grammatically it is singular.

That is why Catalan uses:

• el públic
• és exigent

not a plural verb.

So the grammar follows the singular noun, not the number of people inside the group.

This comes from de + aquesta funció.

In Catalan, de often becomes d' before a vowel:

• de aquesta → d'aquesta

So el públic d'aquesta funció means the audience of this performance/show.

Also, aquesta is feminine singular because funció is a feminine singular noun.

Not in the mathematical or general English sense of function. In this context, funció means a performance, show, or staging.

So aquesta funció means something like this performance or this show.

Catalan funció can sometimes correspond to English function, but in theatre-related contexts it often means performance.

The accent in és helps distinguish it from es, which is a different word.

• és = is
• es = a pronoun used in reflexive or passive-style constructions

So the accent is important here because és is the verb to be.

Many Catalan adjectives have the same form for masculine and feminine singular. Exigent is one of them.

So you get:

• un actor exigent
• una actriu exigent

The plural changes:

• actors exigents
• actrius exigents

In this sentence, exigent agrees with el públic, which is singular, so the singular form is correct.

Catalan uses apostrophes very often to avoid awkward vowel combinations. In this sentence you see three examples:

• L'actor = el actor
• d'assajar = de assajar
• d'aquesta = de aquesta

This is a very normal feature of written Catalan, and you will see it constantly with articles and short grammatical words before vowels.