Ο συναγερμός πυρκαγιάς λειτουργεί.

A natural word-by-word breakdown is:

• Ο = the
• συναγερμός = alarm
• πυρκαγιάς = of fire / fire
• λειτουργεί = works / is functioning / operates

So the whole sentence means The fire alarm works or The fire alarm is functioning.

Ο is the masculine singular definite article, meaning the.

It agrees with συναγερμός, which is a masculine singular noun. In Greek, articles change form depending on gender, number, and case.

Here:

• ο συναγερμός = the alarm

You cannot use just one form of the for every noun in Greek, the way you do in English.

Because πυρκαγιάς is in the genitive case.

The basic dictionary form is:

• η πυρκαγιά = the fire

But in this sentence, Greek uses the genitive to show a relationship like:

• alarm of fire
• in more natural English: fire alarm

So:

• συναγερμός πυρκαγιάς literally = alarm of fire
• natural English = fire alarm

This is very common in Greek. English often uses one noun directly before another, but Greek frequently uses the genitive instead.

Yes, it is a normal and understandable way to say fire alarm.

Literally it is alarm of fire, which is how Greek often expresses this kind of noun combination.

An English speaker may expect something like fire + alarm with two nouns side by side, but Greek often prefers:

• main noun + genitive noun

So this structure is very useful to recognize.

λειτουργεί is present tense, third person singular.

It comes from the verb:

• λειτουργώ = to function / to operate / to work

So λειτουργεί means:

• it works
• it is functioning
• it operates

Because the subject is ο συναγερμός πυρκαγιάς (the fire alarm), the verb is in third person singular.

Usually, no.

λειτουργεί means is working / is functioning properly. It tells you the fire alarm is operational.

If you wanted to say the alarm is actually going off or ringing, Greek would usually use a different verb or expression.

So this sentence is best understood as:

• The fire alarm works
• The fire alarm is functioning

not necessarily:

• The fire alarm is ringing

A rough pronunciation for an English speaker is:

• o si-na-yer-MOS pir-ka-YAS lee-tour-GHEE

A few helpful notes:

• σ is like English s
• γ before ε or ι often sounds like a soft y-like sound
• γιά in πυρκαγιάς sounds roughly like ya
• ει in λειτουργεί sounds like ee

The stress falls on:

• συναγερμός
• πυρκαγιάς
• λειτουργεί

Because the verb λειτουργεί already means works / functions.

In English, learners may think in terms of is working, but Greek does not need a separate is here. The single word λειτουργεί already carries the main verbal meaning.

So:

• Ο συναγερμός πυρκαγιάς λειτουργεί = The fire alarm works / is functioning

There is no missing word.

Yes, Greek word order is more flexible than English word order.

The neutral, straightforward order here is:

• Ο συναγερμός πυρκαγιάς λειτουργεί.

But Greek can sometimes move things around for emphasis.

Still, for a learner, this version is the safest and most natural basic pattern:

• article + noun + genitive modifier + verb

So it is a good model sentence to remember.

You add δεν before the verb:

• Ο συναγερμός πυρκαγιάς δεν λειτουργεί.

That means:

• The fire alarm doesn’t work
• The fire alarm is not functioning

This is a very useful pattern:

• λειτουργεί = works
• δεν λειτουργεί = doesn’t work

The dictionary forms are:

• ο συναγερμός = alarm
• η πυρκαγιά = fire

In the sentence, πυρκαγιάς is not the dictionary form; it is the genitive singular form of πυρκαγιά.

So if you look it up in a dictionary, you would usually search for:

• συναγερμός
• πυρκαγιά

Because it uses ο (the), it most naturally refers to a specific fire alarm:

• The fire alarm is functioning

However, Greek, like English, can sometimes use the singular with the article in a more general sense depending on context. But the most immediate reading is a particular fire alarm.

If you wanted the plural, you would need different forms.

A very useful pattern is:

• [article] + [main noun] + [genitive noun] + [verb]

In this sentence:

• Ο = article
• συναγερμός = main noun
• πυρκαγιάς = genitive noun modifying it
• λειτουργεί = verb

This pattern appears all the time in Greek, especially where English uses noun + noun compounds, such as things like car door, school bus, office manager, and so on. Greek often expresses those relationships with the genitive instead.