Η καταμέτρηση ατόμων αρχίζει μετά την εκκένωση.

A word-by-word breakdown:

• Η = the (feminine singular definite article)
• καταμέτρηση = counting / headcount / counting process
• ατόμων = of persons / of people
  This is the genitive plural of άτομο.
• αρχίζει = begins / starts
• μετά = after
• την = the (feminine singular accusative article)
• εκκένωση = evacuation

So the structure is basically:

• The counting of people begins after the evacuation.

This is a formal, procedural kind of sentence.

Because καταμέτρηση is a noun, and Greek often uses the genitive to show what is being counted, measured, or described by another noun.

So:

• καταμέτρηση ατόμων = counting of people
• literally: counting people’s / of people

This is similar to English noun phrases like:

• number of students
• list of names
• arrival of guests

In Greek, the second noun often goes into the genitive in this kind of construction.

Both are possible, but they do not feel exactly the same.

• καταμέτρηση ατόμων = counting of people / a headcount of people
  This sounds more general or institutional.
• καταμέτρηση των ατόμων = counting of the people / the individuals
  This is more specific: a particular group of people already known from context.

In official notices or procedures, Greek often prefers the more compact style without the second article when speaking generally.

So in a safety or emergency context, καταμέτρηση ατόμων sounds very natural.

Greek often uses the present tense for:

• scheduled events
• procedures
• instructions
• general rules

So αρχίζει here means:

• begins
• starts
• and by context, will begin

This is very similar to English uses like:

• The meeting starts at 9.
• Boarding begins after security clearance.

So although the verb is present tense, the meaning can be procedural or future in context.

Here μετά means after, and in Modern Greek it takes the accusative:

• μετά την εκκένωση = after the evacuation

That is why you see:

• την = feminine accusative singular article
• εκκένωση = accusative singular form

A very useful pattern is:

• μετά + accusative = after

Examples:

• μετά το μάθημα = after the lesson
• μετά τη συνάντηση = after the meeting
• μετά την άσκηση = after the exercise

Because after μετά, the noun must be in the accusative, not the nominative.

Compare:

• η εκκένωση = the evacuation as the subject form
• την εκκένωση = the evacuation as the accusative/object form

So:

• Η εκκένωση αρχίζει... = The evacuation begins...
• μετά την εκκένωση = after the evacuation

The article changes because the case changes.

Yes, εκκένωση is a normal word, but it is fairly formal and often used in:

• safety instructions
• emergency procedures
• official announcements
• military or civil protection contexts

It means evacuation or clearing out.

It comes from the verb:

• εκκενώνω = to evacuate / to empty

So:

• εκκένωση κτιρίου = evacuation of a building
• εκκένωση της περιοχής = evacuation of the area

In everyday speech, people may still use it, especially in news or emergency contexts.

Yes. Καταμέτρηση is a very suitable word when you mean:

• an official count
• a headcount
• a tally
• a systematic counting process

It is more formal and precise than just using a simple verb like μετράω (I count).

In emergency or organizational language, καταμέτρηση is especially natural.

For example:

• καταμέτρηση προσωπικού = staff headcount
• καταμέτρηση μαθητών = counting the students
• καταμέτρηση ψήφων = vote count

So in this sentence, it sounds like an established procedure.

Yes, you could say:

• Η καταμέτρηση ατόμων ξεκινά μετά την εκκένωση.

That would also mean The headcount starts after the evacuation.

The difference is small:

• αρχίζει is a bit more formal or neutral
• ξεκινά can sound slightly more everyday or less formal, though it is still perfectly acceptable

In official written instructions, αρχίζει may feel a little more standard.

Yes, Greek word order is fairly flexible, though not completely free.

The original:

• Η καταμέτρηση ατόμων αρχίζει μετά την εκκένωση.

is natural and straightforward.

You could also hear or see:

• Μετά την εκκένωση αρχίζει η καταμέτρηση ατόμων.

This version puts more emphasis on the time sequence: After the evacuation, the headcount begins.

Both are correct. The original is probably the most neutral for an instruction or notice.

A rough pronunciation guide:

• Η = ee
• καταμέτρηση = ka-ta-ME-tree-see
• ατόμων = a-TO-mon
• αρχίζει = ar-HEE-zee
• μετά = me-TA
• την = teen
• εκκένωση = ek-KE-no-see

A few pronunciation notes:

• χ in αρχίζει is not like English h. It is a stronger sound, like the ch in German ich or a softer version of the sound in Scottish loch, depending on the vowel around it.
• Stress matters in Greek:
  • καταμέτρηση
  • ατόμων
  • αρχίζει
  • μετά
  • εκκένωση

If you ignore stress, your Greek may still be understood, but it will sound much less natural.

Yes, absolutely. It sounds like the kind of Greek you might see in:

• a fire safety procedure
• an evacuation plan
• a school or workplace emergency protocol
• a civil protection instruction

It is not especially conversational; it is more official and procedural.

A native speaker would probably understand it immediately as part of a formal instruction sequence.