Ο πυροσβεστήρας είναι δίπλα στην πυροσβεστική φωλιά.

Ο is the masculine singular definite article, meaning the.

In Greek, nouns normally appear with an article much more often than in English. So:

• ο πυροσβεστήρας = the fire extinguisher

The article has to match the noun’s gender, number, and case.

Greek nouns have grammatical gender, and πυροσβεστήρας is a masculine noun.

That is why it takes the masculine article ο:

• ο πυροσβεστήρας

Many masculine nouns end in -ας, though that ending does not guarantee gender in every single case. In this sentence, you simply learn it as:

• ο πυροσβεστήρας = masculine noun meaning fire extinguisher

είναι means is.

It is the present tense form of to be used for:

• he is
• she is
• it is

So:

• Ο πυροσβεστήρας είναι... = The fire extinguisher is...

A useful point for learners: Greek does not need a separate word for it here. The noun itself tells you what the subject is.

δίπλα means next to, beside, or by the side of.

In this sentence:

• είναι δίπλα στην... = is next to the...

A very common pattern is:

• δίπλα σε + noun
• δίπλα στο / στη / στην / στον...

So δίπλα often works together with σε.

στην is the contracted form of σε την.

So:

• σε + την = στην

This is extremely common in Greek. Similar contractions are:

• σε + το = στο
• σε + τον = στον

So:

• δίπλα στην πυροσβεστική φωλιά
  literally comes from
• δίπλα σε την πυροσβεστική φωλιά

But in normal Greek, the contracted form στην is what you use.

Because φωλιά is a feminine singular noun, and after σε the noun phrase is in the accusative.

For feminine nouns like this one, the accusative singular article is την, which becomes στην after σε.

So:

• η φωλιά = the nest / the cabinet / the fire point
• την φωλιά = the noun in the accusative
• στην φωλιά = in/to/at the ... after contraction

In this sentence, δίπλα στην... requires that structure.

Because πυροσβεστική is an adjective modifying φωλιά, and it must agree with the noun.

Here:

• φωλιά is feminine singular
• so the adjective is also feminine singular

That gives:

• πυροσβεστική φωλιά

This adjective comes from the idea of fire-fighting / fire-service / fire-related. Greek adjectives change form depending on the noun they describe.

Yes, φωλιά literally means nest.

However, in technical or building-safety contexts, πυροσβεστική φωλιά is a set phrase used for a fire-hose cabinet, fire point, or similar fire-safety installation.

So this is one of those cases where the literal meaning of a word does not fully explain the real-world meaning of the whole expression.

It is in the accusative singular.

That is because δίπλα is commonly followed by σε + accusative:

• δίπλα στην πυροσβεστική φωλιά

So even though English just says next to the fire cabinet/fire point, Greek shows the relationship through the preposition σε and the accusative form.

Greek uses definite articles very naturally and very often.

So both noun phrases take the:

• Ο πυροσβεστήρας = the fire extinguisher
• στην πυροσβεστική φωλιά = next to the fire cabinet/fire point

In English, article use is sometimes more flexible, but in Greek it is very normal to include the article with both nouns.

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

The neutral, straightforward order here is:

• Ο πυροσβεστήρας είναι δίπλα στην πυροσβεστική φωλιά.

But Greek could also say things like:

• Δίπλα στην πυροσβεστική φωλιά είναι ο πυροσβεστήρας.

That might sound more marked or place more focus on the location.

Even when the order changes, the articles and endings help show what each word is doing.

It is a compound word related to fire extinguishing.

Very roughly:

• πυρ- / πυρο- relates to fire
• σβήνω / σβεστήρας relates to extinguishing

So πυροσβεστήρας is basically something like fire-extinguisher in structure.

Greek often forms long compounds like this, and once you get used to them, they become easier to recognize.

A rough pronunciation guide is:

• O pee-ro-sve-STEE-ras EH-neh THEE-pla steen pee-ro-sve-STEE-kee fo-LYA

A few helpful notes:

• πυ here sounds roughly like pee
• σβ is a consonant cluster; say it smoothly, without adding a vowel
• είναι is pronounced roughly EH-neh
• δίπλα has the stress on the first syllable: DEE-pla
• φωλιά sounds roughly like fo-LYA

The written accent marks show you where the stress goes:

• πυροσβεστήρας
• είναι
• δίπλα
• πυροσβεστική
• φωλιά