Atâta timp cât scenariul este gata, regizorul lucrează cu actorul.

Here, atâta timp cât is a conjunction meaning as long as or provided that. It introduces a condition for the main action.

So the structure is:

• Atâta timp cât scenariul este gata = the condition
• regizorul lucrează cu actorul = the main statement

Because the sentence starts with a subordinate clause: Atâta timp cât scenariul este gata. In Romanian, when this kind of clause comes before the main clause, it is normally separated by a comma.

So:

• subordinate clause first → comma
• main clause second

Because Romanian usually puts the definite article at the end of the noun instead of using a separate word like English the.

Examples:

• scenariu = a script

• scenariul = the script

• regizor = a director

• regizorul = the director

• actor = an actor
• actorul = the actor

So -ul here is the masculine/neuter singular definite article.

Not exactly. Scenariu is a neuter noun in Romanian.

A useful rule is:

• neuter nouns behave like masculine in the singular
• neuter nouns behave like feminine in the plural

That is why you get singular scenariul, with the same kind of ending you often see on masculine nouns.

Este is the verb is, from a fi = to be.

Gata means ready or finished, and here it works like an adjective/predicative word after este.

So:

• scenariul este gata = the script is ready

A useful thing to know is that gata is often treated as invariable, so it usually does not change form for gender or number the way many other adjectives do.

Because the Romanian verb pattern is a lucra cu cineva = to work with someone.

So:

• lucrează = works
• cu actorul = with the actor

The actor is not the direct object here. It is part of a prepositional phrase introduced by cu.

Because pe is mainly used with certain direct objects, especially definite people.

But in this sentence, actorul is not a direct object. It comes after the preposition cu:

• cu actorul = with the actor

Since actorul is already inside a prepositional phrase, pe is not used.

Both verbs are in the present indicative, 3rd person singular.

• este = he/she/it is
• lucrează = he/she works

They are singular because their subjects are singular:

• scenariul → singular
• regizorul → singular

It is not completely fixed. Romanian word order is fairly flexible.

You could also say:

Regizorul lucrează cu actorul, atâta timp cât scenariul este gata.

Starting with Atâta timp cât... puts the condition first and gives it more emphasis. Starting with Regizorul lucrează... makes the main action come first.

Both patterns are natural, though the punctuation may change depending on style and rhythm.

These two vowels are very common in Romanian and can be tricky for English speakers:

• ă is similar to the weak vowel in English about
• â has no exact English equivalent; it is a central vowel pronounced deeper and tighter than ă

In this sentence:

• Atâta contains â
• cât contains â

So even if the spelling looks unusual at first, those marks are important for correct pronunciation.