Μια άλλη αεροσυνοδός εξήγησε πότε θα αρχίσει η επιβίβαση.

Μια άλλη means another.

Both words are feminine because they go with αεροσυνοδός, which here refers to a female flight attendant. In Greek, words that describe or introduce a noun must agree with it in gender, number, and case.

So here you have:

• μια = feminine singular a / one
• άλλη = feminine singular other / another
• αεροσυνοδός = flight attendant

Together: Μια άλλη αεροσυνοδός = Another flight attendant

No. Αεροσυνοδός is a noun that can be used for either a man or a woman. The form stays the same, and the article or other words around it show the gender.

For example:

• η αεροσυνοδός = the female flight attendant
• ο αεροσυνοδός = the male flight attendant

In your sentence, μια άλλη shows that the person is female.

Εξήγησε is the aorist form, which here gives a simple past meaning: explained.

It is:

• 3rd person singular
• from the verb εξηγώ = I explain

So:

• εξηγώ = I explain
• εξήγησε = he/she explained

Greek often uses the aorist for a completed action in the past, just like English explained.

Because Greek often leaves subject pronouns out when they are not needed.

The verb ending already tells you it is he/she/it. Also, the subject is already stated: Μια άλλη αεροσυνοδός.

So Greek does not need a separate she here.

English:

• Another flight attendant explained...

Greek:

• Μια άλλη αεροσυνοδός εξήγησε...

Adding a pronoun like αυτή would usually sound emphatic, as if you were saying she herself or that one.

Πότε means when, and here it introduces an indirect question.

So:

• direct question: Πότε θα αρχίσει η επιβίβαση; = When will boarding begin?
• indirect question: εξήγησε πότε θα αρχίσει η επιβίβαση = explained when boarding would begin / will begin

This is very common in Greek after verbs like:

• ρωτάω = ask
• ξέρω = know
• εξηγώ = explain
• λέω = say/tell

This is a very common point for English speakers.

Greek keeps θα to express future meaning even after a past verb of reporting. So Greek says:

• εξήγησε πότε θα αρχίσει η επιβίβαση

Literally, that looks like:

• explained when boarding will begin

But natural English usually shifts this to:

• explained when boarding would begin

So the Greek sentence is completely normal. Greek does not have to change will into would the way English often does.

Because θα αρχίσει expresses a single future event: the moment when boarding will begin.

After θα, Greek often shows an aspect difference:

• θα αρχίσει = will begin once, as a complete event
• θα αρχίζει = would suggest something more repeated, habitual, or ongoing in the right context

Here, boarding starts at one particular time, so θα αρχίσει is the natural choice.

Η επιβίβαση means the boarding.

It is a feminine noun:

• η επιβίβαση = the boarding
• της επιβίβασης = of the boarding

It comes from the idea of getting on board a plane, ship, bus, etc.

In airport language, επιβίβαση is the standard word for boarding.

Greek uses the definite article much more often than English.

So where English might say simply boarding, Greek often says η επιβίβαση.

In this sentence, η επιβίβαση refers to the specific boarding process the people are waiting for, so the article sounds natural and expected.

This is very common in Greek with nouns that English often leaves bare.

They are in the nominative because they are subjects of their clauses.

• Μια άλλη αεροσυνοδός is the subject of εξήγησε
• η επιβίβαση is the subject of θα αρχίσει

So both noun phrases are nominative singular.

Yes, Greek word order is more flexible than English, but the given order is the most neutral and natural.

Neutral order:

• Μια άλλη αεροσυνοδός εξήγησε πότε θα αρχίσει η επιβίβαση.

You can move things around for emphasis, but then the focus changes. For example, Greek might front a phrase to highlight it. Still, for a learner, the sentence as given is the best standard model.

A rough pronunciation is:

Mya AL-lee ae-ro-see-no-THOS ex-I-yi-se PO-te tha ar-HEE-si ee epi-VEE-vasi

A few notes:

• αι in αεροσυνοδός is pronounced separately here: a-e
• θ sounds like th in think
• χ in αρχίσει is like a harsher sound, not an English h
• the stressed syllables are:
  • άλλη
  • αεροσυνοδός
  • εξήγησε
  • πότε
  • αρχίσει
  • επιβίβαση