Learn Hardcore Greek: Μην ανοίγεις την μπαλκονόπορτα, κάνει κρύο.

δεν is used for statements:
- Δεν ανοίγεις την πόρτα. = You are not opening the door.
μη(ν) is used for commands / prohibitions / wishes:
- Μην ανοίγεις την πόρτα. = Don’t open the door.

Here we are giving a negative command, so μην is the correct choice, not δεν.

Why is it spelled μην and not μη here?

The little ν at the end is kept before vowels and certain consonants, mainly to make pronunciation smoother.

Before a vowel: μην ανοίγεις (a-noí-gis) – we keep ν.
Before many consonants, you often see just μη:
- Μη μιλάς. = Don’t talk.

In careful writing, the usual rule is: keep the final -ν of μην, τον, την before a vowel or before the consonants κ, π, τ, ξ, ψ, μπ, ντ, γκ, τσ, τζ.
Since ανοίγεις starts with a vowel (α), we write μην.

Why is the verb ανοίγεις (present) used, and not the imperative άνοιξε or μην ανοίξεις?

Positive and negative commands are formed differently in Greek:

Positive command:
- Άνοιξε την μπαλκονόπορτα. = Open the balcony door.
Negative command (prohibition):
- Μην ανοίξεις την μπαλκονόπορτα. (aorist)
- Μην ανοίγεις την μπαλκονόπορτα. (present)

Both μην ανοίξεις and μην ανοίγεις are possible, but they have a nuance:

Μην ανοίξεις = Don’t open it (this time / even once).
Μην ανοίγεις = Don’t (be) opening it / Don’t keep opening it (more continuous or general).

In everyday speech, μην ανοίγεις is also very commonly used for a simple “don’t open (now)”, especially when talking about something that tends to be opened repeatedly, like a door or a window.

Where is the word “you” in the Greek sentence? There is no εσύ.

Greek normally drops subject pronouns when they are clear from the verb ending. The verb ending -εις in ανοίγεις already tells us it is 2nd person singular (“you”):

ανοίγω = I open
ανοίγεις = you (singular) open
ανοίγει = he / she / it opens

So εσύ is understood:
(Εσύ) μην ανοίγεις την μπαλκονόπορτα. = You, don’t open the balcony door.

The explicit εσύ is only added for emphasis:
Εσύ μην ανοίγεις την μπαλκονόπορτα. (You, specifically, don’t open…)

What is την doing here, and why this form of the article?

την is the definite article (“the”) in feminine accusative singular.

Nominative (subject): η μπαλκονόπορτα = the balcony door
Accusative (direct object): την μπαλκονόπορτα = the balcony door

In our sentence, την μπαλκονόπορτα is the direct object of the verb ανοίγεις (what you are not supposed to open), so we must use the accusative form of the article, την.

Why is there a ν in την μπαλκονόπορτα, but people sometimes write τη without ν?

Modern Greek often drops the final -ν of τον / την / έναν except before vowels and certain consonants. The usual guideline:

Keep -ν before:
- vowels: την αδελφή
- κ, π, τ, ξ, ψ, μπ, ντ, γκ, τσ, τζ:
  - την πόρτα, τον πατέρα, την μπαλκονόπορτα
Drop -ν more often before other consonants (especially in informal writing):
- τη μάνα, τη χώρα (you will also see την in careful writing; both occur).

Since μπαλκονόπορτα begins with μπ, which represents a /b/ sound and falls into the “keep the -ν” group, we write την μπαλκονόπορτα.

What exactly does μπαλκονόπορτα mean? Is it just “balcony door”?

Yes, μπαλκονόπορτα means “balcony door”, specifically the door that leads to the balcony.

It is a compound noun:

μπαλκόνι = balcony
πόρτα = door
→ μπαλκονόπορτα (literally “balcony-door”)

Grammatical details:

Gender: feminine
Basic form: η μπαλκονόπορτα
Accusative: την μπαλκονόπορτα

Pronunciation (approx.): bal-ko-NÓ-por-ta, with the stress on νό.

Why do we say κάνει κρύο and not είναι κρύο?

For weather and general environmental conditions, Greek often uses κάνει or έχει, not είναι, where English uses “it is …”:

Κάνει κρύο. = It’s cold.
Κάνει ζέστη. = It’s hot / warm.
Έχει κρύο. = It’s cold.
Έχει ήλιο. = It’s sunny.

Literally κάνει κρύο is like “it makes cold”, but it is an idiomatic set phrase meaning “it is cold (weatherwise)”.
Είναι κρύο usually describes a specific thing as cold:

Το νερό είναι κρύο. = The water is cold.

Who or what is the subject of κάνει in κάνει κρύο? There is no “it”.

This is an impersonal expression. Greek often leaves out an explicit subject in such cases:

Κάνει κρύο. = It’s cold.
Βρέχει. = It’s raining.
Χιονίζει. = It’s snowing.

English needs a dummy subject “it”, but Greek simply uses the 3rd person singular of the verb without any subject word. The verb form itself (like κάνει) is enough.

Is the comma important here? Could we add “because”, like γιατί κάνει κρύο?

The comma is natural here because we have two clauses:

Μην ανοίγεις την μπαλκονόπορτα,
κάνει κρύο.

The second clause gives a reason, so you can also make that explicit:

Μην ανοίγεις την μπαλκονόπορτα, γιατί κάνει κρύο.
= Don’t open the balcony door, because it’s cold.

Both versions are fine. Without γιατί, the causal relationship is still obvious from the context and the comma.

How would I say this to more than one person, or in a polite / formal way?

You use the 2nd person plural form ανοίγετε for both:

Μην ανοίγετε την μπαλκονόπορτα, κάνει κρύο.

This can mean:

Talking to several people: “You (all), don’t open the balcony door…”
Talking politely / formally to one person (using plural for politeness).

So:

Informal singular: Μην ανοίγεις την μπαλκονόπορτα, κάνει κρύο.
Plural or polite: Μην ανοίγετε την μπαλκονόπορτα, κάνει κρύο.

Can I say Μην ανοίγεις το μπαλκόνι instead of την μπαλκονόπορτα?

Not if you mean “don’t open the balcony door”.

το μπαλκόνι = the balcony (the outside area itself)
η μπαλκονόπορτα = the balcony door

Μην ανοίγεις το μπαλκόνι would literally be “don’t open the balcony”, which sounds odd or wrong. To talk about opening/closing, you must refer to the door or window, so την μπαλκονόπορτα is the natural choice here.