Learn Hardcore Greek: Στο γκαράζ του φίλου μου υπάρχει μόνο ένα ποδήλατο και ένα παλιό αυτοκίνητο, οπότε όλα χωράνε άνετα. - In my friend’s garage there is only one bicycle and an old car, so everything fits easily.

So στο γκαράζ literally means “in the garage”. In normal Greek you must use the contracted form (στο, στον, στη(ν), etc.) in speech and almost always in writing.

What gender is γκαράζ, and why doesn’t it change form?

γκαράζ is treated as a neuter noun in Greek, but it is indeclinable (its form doesn’t change).

Singular: το γκαράζ
Plural: τα γκαράζ (same word, only the article changes)

Many loanwords ending in a consonant (μπαρ, γκαράζ, πάρτι, φιλμ, σπα) behave like this. The gender is shown only by the article, not by an ending on the noun itself.

How does του φίλου μου work exactly? Why are there two words for “my friend”?

του φίλου μου literally means “of my friend” and is in the genitive case:

ο φίλος → του φίλου (genitive: of the friend)
μου = my / of me (unstressed possessive pronoun)

So:

το γκαράζ του φίλου μου = the garage of my friend

Both του φίλου and μου show possession, but:

του φίλου says whose garage it is (the friend’s).
μου says whose friend it is (my friend).

Word order is normally:

το κάτι του φίλου μου = the something of my friend
The clitic μου always comes after the noun or noun phrase it belongs to: ο φίλος μου, το γκαράζ του φίλου μου.

Why is it υπάρχει and not υπάρχουν, since there are two things?

Strictly speaking, with more than one thing you expect the plural:

Υπάρχουν ένα ποδήλατο και ένα παλιό αυτοκίνητο.

However, in everyday speech many Greeks use the singular υπάρχει when:

The first noun after it is singular, and
The speaker thinks of the listed items as one set (“only a bike and an old car, nothing more”).

So:

Υπάρχει μόνο ένα ποδήλατο και ένα παλιό αυτοκίνητο
is very natural in spoken Greek, though a grammar book or exam might prefer υπάρχουν.

Both forms are understood; υπάρχουν is the more “school-correct” agreement.

What’s the difference between υπάρχει and είναι for “there is / there are”?

Both can translate as “there is / there are”, but not in the same contexts.

υπάρχει / υπάρχουν: literally “exists / exist”, used to introduce the existence of something, often for the first time:
- Στο γκαράζ υπάρχει ένα ποδήλατο.
  There is a bicycle in the garage.
- Υπάρχουν πολλά προβλήματα.
  There are many problems.
είναι: literally “is / are”, used more for identifying or describing:
- Το ποδήλατο είναι στο γκαράζ.
  The bicycle is in the garage.
- Στο γκαράζ είναι το ποδήλατό μου.
  It’s my bicycle that is in the garage.

In your sentence we are stating what exists in the garage, so υπάρχει is the natural choice.

What exactly does μόνο modify here?

μόνο is an adverb meaning “only” and it focuses the phrase that follows it:

μόνο ένα ποδήλατο και ένα παλιό αυτοκίνητο

So the meaning is:
In my friend’s garage there is only a bicycle and an old car (and nothing else).

It does not primarily mean “only one bicycle”; it means these are the only items present. The fact that there is one of each is secondary here.

Is ένα here the number “one” or the indefinite article “a”?

In modern Greek, ένα does double duty:

as the number “one”, and
as the neuter singular indefinite article “a / an”.

In this sentence it mainly works like “a”:

ένα ποδήλατο = a bicycle
ένα παλιό αυτοκίνητο = an old car

If you wanted to stress the number “one”, you would typically emphasize it or add something like μόνο ένα in a context where number really matters:

Έχει μόνο ένα ποδήλατο, όχι δύο.
He has only one bicycle, not two.

Why is it ένα παλιό αυτοκίνητο and not ένα αυτοκίνητο παλιό?

In Greek, the normal position for an adjective is before the noun:

ένα παλιό αυτοκίνητο = an old car
ένα μεγάλο σπίτι = a big house

So παλιό appears before αυτοκίνητο, and it agrees with it:

παλιό: neuter, singular, nominative/accusative (same as ένα, αυτοκίνητο)

You can say ένα αυτοκίνητο παλιό, but that sounds:

more marked / emphatic, or
like you’re adding “old” as extra information: “a car, (and it’s) old”.

In neutral description, use adjective + noun: παλιό αυτοκίνητο.

What does οπότε mean here, and how is it different from other “so / therefore” words like γι’ αυτό or άρα?

οπότε introduces a result or consequence, roughly “so / and so / so then”:

..., οπότε όλα χωράνε άνετα.
..., so everything fits comfortably.

Comparison:

οπότε – very common in speech; often sounds a bit casual / narrative.
γι’ αυτό – literally “for this reason”, more like “that’s why”.
άρα – a bit more formal / logical, like “therefore”.
έτσι – “so / in this way”, broader use.

Here οπότε nicely links the situation (only two vehicles) to the result (they all fit easily).

Why is there a comma before οπότε?

Because οπότε introduces a new clause expressing a result:

Clause 1: Στο γκαράζ του φίλου μου υπάρχει μόνο ένα ποδήλατο και ένα παλιό αυτοκίνητο
Clause 2: οπότε όλα χωράνε άνετα

Greek usually separates such clauses with a comma, especially with connectors like οπότε, γιατί, αλλά, όμως etc.:

Έχει μεγάλο γκαράζ, οπότε όλα χωράνε άνετα.
Έχει μεγάλο γκαράζ, αλλά δεν έχει αυτοκίνητο.

What does όλα refer to, and why is it neuter plural?

όλα is the neuter plural form of όλος and functions here as a pronoun meaning “everything / all (of them)”.

It refers back to the things mentioned:

ένα ποδήλατο και ένα παλιό αυτοκίνητο → όλα (all of them)

Greek commonly uses neuter plural pronouns (and adjectives) for mixed groups of objects:

Τα βιβλία και τα τετράδια είναι στο τραπέζι. Όλα είναι καινούρια.
The books and the notebooks are on the table. They’re all new.

So όλα χωράνε άνετα = they all fit comfortably.

Why is it χωράνε and not χωρούν? Are both correct?

Yes, both are correct; they are two forms of the same verb χωράω / χωρώ (to fit / to have room).

3rd person plural present:

χωράνε – more colloquial / everyday
χωρούν (often χωρούνε in speech) – more standard / formal

So you can say:

Όλα χωράνε άνετα. (very common in spoken Greek)
Όλα χωρούν άνετα. (slightly more formal / written)

The meaning is the same.

What is άνετα, and why doesn’t it change form like an adjective?

άνετα here is an adverb meaning “comfortably / easily”.

Adjective: άνετος (comfortable)
- ο άνετος καναπές = the comfortable sofa
Adverb: άνετα (comfortably)
- Χωράνε άνετα. = They fit comfortably.

Adverbs in Greek (like άνετα, καλά, γρήγορα) do not agree in gender, number, or case. They keep one form and modify verbs, adjectives, or other adverbs.

So άνετα modifies the verb χωράνε, not όλα.