Η άσκηση εκκένωσης αρχίζει τώρα.

Η is the feminine singular definite article, so it means the.

It is used because άσκηση is a feminine singular noun:

• η άσκηση = the drill / the exercise

Greek articles change for gender, number, and case, unlike English the, which always stays the same.

Here is the breakdown:

• Η = the
• άσκηση = drill / exercise
• εκκένωσης = of evacuation
• αρχίζει = begins / is beginning
• τώρα = now

So the structure is literally:

• Η άσκηση εκκένωσης = the evacuation drill
• αρχίζει τώρα = begins now

Because εκκένωσης is in the genitive case.

The basic noun is:

• η εκκένωση = the evacuation

But after another noun, Greek often uses the genitive to express of:

• άσκηση εκκένωσης = drill of evacuation = evacuation drill

So:

• εκκένωση = nominative form
• εκκένωσης = genitive form

This is very common in Greek noun combinations.

Yes. It is a very natural Greek structure.

Greek often expresses noun-noun combinations by using:

• a main noun
• followed by a second noun in the genitive

So instead of making a direct compound like English often does, Greek says something closer to:

• drill of evacuation

Other similar patterns are:

• στάση λεωφορείου = bus stop literally stop of bus
• πόρτα σπιτιού = house door literally door of house

So άσκηση εκκένωσης is completely normal.

Because αρχίζει already means begins or is beginning.

Greek does not need a separate auxiliary verb like English sometimes does.
In English, you might say:

• begins now
• is beginning now
• is starting now

In Greek, αρχίζει can cover this idea by itself, depending on context.

So:

• Η άσκηση εκκένωσης αρχίζει τώρα. can naturally mean
• The evacuation drill begins now. or
• The evacuation drill is beginning now.

Greek usually does not need subject pronouns when the verb ending already shows the subject.

The verb αρχίζει is third person singular, so it already tells you:

• he/she/it begins
• or, here, it begins

Because η άσκηση εκκένωσης is already the subject, adding a pronoun would be unnecessary.

This is called a pro-drop language feature.

αρχίζει is:

• present tense
• 3rd person singular
• from the verb αρχίζω = to begin / to start

A few useful forms:

• αρχίζω = I begin
• αρχίζεις = you begin
• αρχίζει = he/she/it begins
• αρχίζουμε = we begin
• αρχίζετε = you begin
• αρχίζουν = they begin

In this sentence, the subject is singular:

• Η άσκηση εκκένωσης
  so the verb is also singular:
• αρχίζει

A simple pronunciation guide is:

ee AS-kee-see ek-KE-no-sees ar-KHEE-zee TO-ra

A few notes:

• Η sounds like ee
• άσκηση has stress on the first syllable: AS
• εκκένωσης has stress on KE
• αρχίζει has stress on KHEE
• τώρα has stress on TO

A more careful approximation:

• Η άσκηση εκκένωσης αρχίζει τώρα
• ee AS-ki-si ek-KE-no-sis ar-KHI-zi TO-ra

If you know IPA, it is roughly:

• [i ˈaskisi ekˈcenosis arˈxizi ˈtora]

Greek stress is very important, and the written accent shows you where the stress goes.

In this sentence:

• άσκηση → stress on ά
• εκκένωσης → stress on κέ
• αρχίζει → stress on ζί
• τώρα → stress on τώ

If you move the stress, the word may sound wrong or unnatural. So it is worth learning each word together with its accent.

Yes, Greek word order is more flexible than English, although this sentence is the most neutral and natural order.

Standard order:

• Η άσκηση εκκένωσης αρχίζει τώρα.

You could also hear:

• Τώρα αρχίζει η άσκηση εκκένωσης.
• Αρχίζει τώρα η άσκηση εκκένωσης.

These versions change the focus or emphasis slightly:

• starting with τώρα emphasizes now
• starting with αρχίζει emphasizes the action begins

But the original version is a very normal announcement-style sentence.

Not always. άσκηση can mean different things depending on context, including:

• exercise
• practice
• drill
• training exercise

In this sentence, because it is followed by εκκένωσης, the best translation is:

• evacuation drill

So the context determines the most natural English choice.

Because the word comes from εκκένωση, which is normally spelled with double κ.

This is standard spelling, not something special only in this sentence.

You do not need to separate the two κ strongly in normal speech the way English learners sometimes expect from double consonants in other languages. The important thing is mainly to learn the correct spelling and recognize the word family:

• εκκένωση = evacuation
• εκκενώνω = to evacuate
• εκκένωσης = of evacuation

Yes. A common alternative is ξεκινά or ξεκινάει, meaning starts.

For example:

• Η άσκηση εκκένωσης ξεκινά τώρα.
• Η άσκηση εκκένωσης ξεκινάει τώρα.

These are also natural.

Very roughly:

• αρχίζει can sound a bit more like begins
• ξεκινά / ξεκινάει can sound a bit more like starts

But in many everyday contexts, they are close in meaning.

It sounds neutral to slightly formal, which fits a public announcement very well.

That is why it works naturally for situations like:

• a school announcement
• a safety drill
• a building loudspeaker message
• an emergency procedure notice

It is clear, standard, and appropriate for official communication.