Τη στιγμή που μιλάει ο υποβολέας, ο ηθοποιός θυμάται την ατάκα.

Because τη στιγμή (που) is a fixed time expression meaning at the moment (when).

• η στιγμή = the moment as a subject or dictionary form
• τη στιγμή = accusative, used here adverbially to express time

Greek often uses the accusative in expressions of time, especially in phrases like:

• την ώρα που = while / at the time when
• τη στιγμή που = the moment when

So here τη στιγμή που μιλάει... means at the moment when ... is speaking.

Here που means when, not who or that.

In this sentence, it introduces a time clause:

• Τη στιγμή που μιλάει ο υποβολέας = At the moment when the prompter is speaking

Greek που is very common and can have several functions. After expressions like τη στιγμή, την ώρα, τη μέρα, it often works like when.

Yes. In this sentence, μιλάει and μιλά are both correct and mean he/she speaks / is speaking.

So you could also say:

• Τη στιγμή που μιλά ο υποβολέας...

The form μιλάει is a very common present-tense form of μιλάω / μιλώ. In everyday Greek, both versions are standard.

Because ο υποβολέας is in the nominative case, which is the normal case for the subject.

• ο υποβολέας = the prompter (nominative)
• τον υποβολέα would be the prompter as a direct object (accusative)

So μιλάει ο υποβολέας means the prompter is speaking, not someone is speaking the prompter.

Greek word order is flexible, so case endings and articles help you identify grammatical roles.

Υποβολέας means prompter in a theater context: the person who helps actors by feeding them their lines if needed.

It comes from the world of drama and stage performance, so it fits well with ηθοποιός and ατάκα in the same sentence.

Because θυμάμαι is a verb with middle/passive-type endings but an active meaning.

So:

• θυμάμαι = I remember
• θυμάται = he/she remembers

This is very common in Greek. Not every verb ending in -μαι is truly passive in meaning.

So in this sentence:

• ο ηθοποιός θυμάται την ατάκα = the actor remembers the line

Because την ατάκα is the direct object, so it has to be in the accusative case.

• η ατάκα = nominative, dictionary form, the line
• την ατάκα = accusative, the line as the thing being remembered

The verb θυμάται takes a direct object, and that object here is the line.

Here ατάκα means line in the theatrical sense: a piece of dialogue an actor says.

So:

• ο ηθοποιός θυμάται την ατάκα = the actor remembers the line

In everyday Greek, ατάκα can also mean a smart remark, one-liner, or snappy comment, but in this sentence the theater meaning is the natural one.

Yes. The sentence presents the two actions as simultaneous.

• μιλάει ο υποβολέας = the prompter is speaking
• ο ηθοποιός θυμάται την ατάκα = the actor remembers the line

Together, the meaning is that the actor remembers the line at the moment when the prompter is speaking.

The Greek present tense here works much like English is speaking / remembers in a live situation or narrative description.

Yes, you could say:

• Όταν μιλάει ο υποβολέας, ο ηθοποιός θυμάται την ατάκα.

That would also be grammatical.

The difference is nuance:

• όταν = general when
• τη στιγμή που = more specific, at the moment when, just as

So the original sentence feels a little more vivid and precise.

Yes. Greek word order is flexible, although the original order is very natural.

For example, you could also say:

• Ο ηθοποιός θυμάται την ατάκα τη στιγμή που μιλάει ο υποβολέας.

This still means the same thing. The difference is mainly emphasis:

• starting with Τη στιγμή που... sets the scene first
• starting with Ο ηθοποιός... focuses first on the actor

Because the sentence starts with a subordinate time clause, and Greek normally separates that from the main clause with a comma.

So the structure is:

• Τη στιγμή που μιλάει ο υποβολέας, = subordinate time clause
• ο ηθοποιός θυμάται την ατάκα. = main clause

This is similar to English punctuation in sentences like:

• When the prompter speaks, the actor remembers the line.

Yes. Ηθοποιός can refer to either a male or a female actor, and the article shows the gender here.

• ο ηθοποιός = the actor (male)
• η ηθοποιός = the actress / the actor (female)

So in this sentence, ο ηθοποιός specifically refers to a man.