Ο υπεύθυνος ορόφου ελέγχει την πυροσβεστική φωλιά.

ορόφου is the genitive singular of όροφος (floor/storey).

Here it depends on υπεύθυνος and shows what area the person is responsible for. So:

• ο υπεύθυνος ορόφου = the floor supervisor / the person in charge of the floor

A very literal breakdown would be something like the responsible person of the floor, but English expresses this more naturally in other ways.

Also note the form change:

• όροφος → nominative
• ορόφου → genitive

Greek often omits the article in expressions that work almost like job titles or set labels.

So:

• ο υπεύθυνος ορόφου sounds like floor supervisor
• ο υπεύθυνος του ορόφου would sound more like the person in charge of the floor, with a more specific of the floor feeling

Both can exist, but the version without the article is very natural in administrative or professional wording.

ελέγχει is:

• present tense
• 3rd person singular
• from the verb ελέγχω (to check / inspect / control)

So it means:

• he checks
• she checks
• it checks

Depending on context, Greek present tense can also correspond to English is checking.

Because Greek is a pro-drop language: the subject pronoun is often omitted when the verb already makes the person clear.

Since ελέγχει already means he/she checks, Greek does not need to say αυτός or αυτή unless there is emphasis or contrast.

So the sentence sounds natural without a separate subject pronoun.

Because this is the direct object of the verb, so it must be in the accusative.

The base form is:

• η πυροσβεστική φωλιά = nominative

But after the verb, as the thing being checked, it becomes:

• την πυροσβεστική φωλιά = accusative

Both the article and the adjective agree with the noun:

• την = feminine singular accusative article
• πυροσβεστική = feminine singular accusative adjective
• φωλιά = feminine singular noun

This is the so-called final nu.

In modern Greek, τη and την are both possible in some environments, but the -ν is normally kept before a vowel and before certain consonants, including π.

Since the next word is πυροσβεστική, which starts with π, την πυροσβεστική φωλιά is the expected form.

It can be both.

As an adjective, υπεύθυνος means responsible.

But Greek often uses adjectives as nouns when the meaning is understood. So:

• ο υπεύθυνος = the person in charge, the supervisor, the responsible person

In this sentence, it is functioning like a noun phrase, not just a descriptive adjective.

Yes. Greek word order is more flexible than English because case endings and articles help show what each word is doing.

The given sentence has a neutral, standard order:

• Ο υπεύθυνος ορόφου ελέγχει την πυροσβεστική φωλιά.

But Greek could also say:

• Την πυροσβεστική φωλιά ελέγχει ο υπεύθυνος ορόφου.

That version puts more focus on the fire-hose cabinet/station as the thing being checked.

So the original order is the most neutral and straightforward one.

Yes, φωλιά literally means nest.

But in this expression, πυροσβεστική φωλιά is a fixed term in Greek for the fire-protection installation, typically the fire hose cabinet/station in a building.

So this is one of those cases where the literal meaning of the individual words does not fully explain the real-world meaning of the whole expression. It is best learned as a set phrase.

Then the subject would become feminine:

• Η υπεύθυνη ορόφου ελέγχει την πυροσβεστική φωλιά.

Changes:

• Ο → Η
• υπεύθυνος → υπεύθυνη

The verb ελέγχει stays the same, because in Greek the verb does not change between he checks and she checks in the 3rd person singular present.

Here are the main dictionary forms:

• υπεύθυνος → dictionary form already shown here
• όροφος → dictionary form of ορόφου
• ελέγχω → dictionary form of ελέγχει
• πυροσβεστικός / πυροσβεστική / πυροσβεστικό → adjective base form
• φωλιά → dictionary form already shown here

This is useful because Greek words often change form depending on case, number, gender, tense, or person, so learners need to know how to get back to the dictionary entry.