Περιμένω στη δεύτερη έξοδο του μετρό, γιατί η κεντρική είσοδος είναι γεμάτη κόσμο.

Στη is the contracted form of σε τη.

• σε = at / in / to
• τη = the feminine accusative singular form of the

So:

• σε τη δεύτερη έξοδο → στη δεύτερη έξοδο

This contraction is extremely common in everyday Greek.

You will also see:

• στο = σε το
• στον = σε τον
• στην = σε την

Here, έξοδο is feminine, so στη(ν) is the correct form.

Δεύτερη is the feminine singular accusative form of second, matching έξοδο.

The noun έξοδος is feminine:

• nominative: η έξοδος
• accusative: την έξοδο

Because the preposition σε takes the accusative, both the article and the adjective have to match that case:

• στη δεύτερη έξοδο

So the pattern is:

• article: τη / την
• adjective: δεύτερη
• noun: έξοδο

All three agree in gender, number, and case.

Because it is in the accusative case.

The basic dictionary form is:

• η έξοδος = the exit

But after σε, Greek normally uses the accusative:

• στην έξοδο = at/to the exit

So:

• nominative: η έξοδος
• accusative: την έξοδο

This is very common in Greek. Many feminine nouns ending in -ος are feminine and change like this.

Του μετρό means of the metro.

Greek often uses the genitive where English uses of or a noun used attributively.

So:

• η έξοδος του μετρό = the metro exit / the exit of the metro
• η είσοδος του μετρό = the metro entrance / the entrance of the metro

Το μετρό is neuter:

• nominative/accusative: το μετρό
• genitive: του μετρό

Notice that μετρό itself does not change in form here; the article changes to show the genitive:

• το → του

They are opposites:

• η έξοδος = exit
• η είσοδος = entrance

Both are feminine nouns and look similar because they are built in a parallel way:

• έξ- relates to going out
• είσ- relates to going in

In the sentence:

• στη δεύτερη έξοδο του μετρό = at the second exit of the metro
• η κεντρική είσοδος = the main/central entrance

Because η κεντρική είσοδος is the subject of the second clause, so it is in the nominative.

Breakdown:

• η = feminine nominative singular article
• κεντρική = feminine nominative singular adjective
• είσοδος = feminine nominative singular noun

So this phrase means the main entrance and functions as the subject of είναι γεμάτη κόσμο.

If it were in the accusative, it would change:

• την κεντρική είσοδο

Both are possible, but they mean things a little differently.

• είναι γεμάτη κόσμο = it is full of people / crowded
• έχει πολύ κόσμο = it has a lot of people / there are many people there

In your sentence, γεμάτη κόσμο describes the entrance as full/crowded, so it works like an adjective phrase after είναι.

Γεμάτη agrees with η κεντρική είσοδος:

• feminine singular subject → γεμάτη

If the subject were masculine:

• ο χώρος είναι γεμάτος κόσμο

If neuter:

• το μέρος είναι γεμάτο κόσμο

Good question. In Greek, both patterns are used:

• γεμάτος/γεμάτη/γεμάτο από...
• γεμάτος/γεμάτη/γεμάτο ...

So both of these are natural:

• η είσοδος είναι γεμάτη από κόσμο
• η είσοδος είναι γεμάτη κόσμο

The version without από is very common and natural, especially with things like:

• κόσμο
• αυτοκίνητα
• νερό
• σκόνη

So γεμάτη κόσμο simply means full of people.

Περιμένω is the present tense, first person singular: I wait / I am waiting.

Greek present tense often covers both:

• I wait
• I am waiting

So Περιμένω can mean:

• I’m waiting
• I wait, depending on context

In this sentence, the natural English translation is usually I’m waiting because it describes a current situation.

Because γιατί introduces the reason clause: because the main entrance is crowded.

Greek punctuation often uses a comma before clauses introduced by γιατί, especially when the second clause gives an explanation.

So the structure is:

• main clause: Περιμένω στη δεύτερη έξοδο του μετρό
• reason clause: γιατί η κεντρική είσοδος είναι γεμάτη κόσμο

The comma helps separate the two ideas clearly.

No. Γιατί can mean two different things:

• why?
• because

You understand which meaning it has from context.

Examples:

• Γιατί περιμένεις εδώ; = Why are you waiting here?
• Περιμένω εδώ, γιατί βρέχει. = I’m waiting here because it’s raining.

In your sentence, γιατί clearly means because, since it introduces an explanation.

Because κόσμος in Greek can mean people / crowd / the public as a collective noun.

So:

• πολύς κόσμος = a lot of people
• γεμάτο κόσμο = full of people
• έχει κόσμο = there are people / it’s busy

Here, κόσμο is accusative singular, but the meaning is collective, not just one person.

This is very natural Greek usage.

Yes. Both can occur, but στη is the more usual contracted everyday form.

So these are equivalent:

• στη δεύτερη έξοδο
• στην δεύτερη έξοδο

In modern standard Greek, speakers very often prefer the contracted form before consonants:

• στη δεύτερη έξοδο

Before a vowel, στην may be kept more often for smoother pronunciation.

Yes, Greek word order is more flexible than English, though not completely free.

The given sentence is neutral and natural:

• Περιμένω στη δεύτερη έξοδο του μετρό, γιατί η κεντρική είσοδος είναι γεμάτη κόσμο.

You could rearrange parts for emphasis, for example:

• Στη δεύτερη έξοδο του μετρό περιμένω, γιατί η κεντρική είσοδος είναι γεμάτη κόσμο.

That puts more focus on where you are waiting.

But the original version is the most straightforward and natural for a learner to imitate.

It is a very good example because it shows adjectives agreeing with feminine nouns in two different cases.

1. στη δεύτερη έξοδο

   • noun: έξοδο → feminine singular accusative
   • adjective: δεύτερη → feminine singular accusative

2. η κεντρική είσοδος

   • noun: είσοδος → feminine singular nominative
   • adjective: κεντρική → feminine singular nominative

3. η κεντρική είσοδος είναι γεμάτη

   • subject: η κεντρική είσοδος → feminine singular
   • adjective/predicate: γεμάτη → feminine singular

So Greek adjectives must match the noun they describe in:

• gender
• number
• case

This sentence shows that very clearly.