Learn Hardcore Greek: Αύριο έχω συνέντευξη, οπότε ζεσταίνω το σίδερο και σιδερώνω το πουκάμισό μου. - Tomorrow I have an interview, so I heat up the iron and iron my shirt.

In Greek, the present tense is very often used for scheduled or arranged future events, especially when there is a time word like αύριο (tomorrow).

Αύριο έχω συνέντευξη.
= Tomorrow I have an interview. (It’s fixed, on my schedule.)
Θα έχω συνέντευξη αύριο.
Also correct, but feels a bit more neutral or slightly more “future-focused”, less like a calendar entry.

It’s very similar to English:

Tomorrow I *have an interview* (present, but future meaning) vs
Tomorrow I *will have an interview.*

So Αύριο έχω συνέντευξη is completely natural and common.

Can I change the word order and say Έχω συνέντευξη αύριο instead of Αύριο έχω συνέντευξη? Is there a difference?

Yes, you can say both:

Αύριο έχω συνέντευξη.
Έχω συνέντευξη αύριο.

Both are grammatically correct and mean I have an interview tomorrow.

Small nuance:

Αύριο έχω συνέντευξη puts a bit more emphasis on when (tomorrow).
Έχω συνέντευξη αύριο starts with the fact that you have an interview, and then adds when.

In everyday speech, both orders are very common.

Why is there no article in έχω συνέντευξη? Why not έχω μια συνέντευξη?

Both are possible, but they’re used slightly differently:

Έχω συνέντευξη.
Literally “I have interview.” Greek often drops the article in certain fixed, abstract or “activity” contexts, similar to English:
- Έχω δουλειά. – I have (some) work.
- Έχω μάθημα. – I have class / lesson.
- Έχω ραντεβού. – I have an appointment.
Έχω συνέντευξη fits this pattern: it’s treated more like “I have an interview (session/event)” in general.
Έχω μια συνέντευξη.
This emphasizes “one” interview, as a countable event. For example:
- Αύριο έχω μια συνέντευξη και μεθαύριο άλλη μία.
  Tomorrow I have one interview and the day after tomorrow another one.

So in your sentence, Αύριο έχω συνέντευξη is the most natural, neutral choice.

What exactly does οπότε mean here? Is it the same as “so” or “therefore”? Could I use άρα or γι’ αυτό instead?

In this sentence, οπότε means “so / therefore / and so” and introduces a result:

Αύριο έχω συνέντευξη, οπότε ζεσταίνω το σίδερο…
Tomorrow I have an interview, so I’m heating up the iron…

You could replace it with:

γι’ αυτό – for this reason / that’s why
άρα – thus / therefore (a bit more formal / logical)

Examples:

Αύριο έχω συνέντευξη, γι’ αυτό ζεσταίνω το σίδερο…
Αύριο έχω συνέντευξη, άρα ζεσταίνω το σίδερο…

Οπότε is very common in spoken and informal written Greek, and often feels a bit lighter and more conversational than γι’ αυτό or άρα.

Is the comma before οπότε necessary?

Yes, it is normal and recommended to put a comma before οπότε when it introduces a result clause like this:

Αύριο έχω συνέντευξη, οπότε ζεσταίνω το σίδερο…

You’re separating:

main clause: Αύριο έχω συνέντευξη
result clause: οπότε ζεσταίνω το σίδερο και σιδερώνω το πουκάμισό μου

So the comma is used much like in English:

Tomorrow I have an interview, so I’m heating up the iron…

Why is ζεσταίνω used and not something like θερμαίνω? What’s the nuance of ζεσταίνω?

Ζεσταίνω is the everyday verb for “to warm / heat (something up)”, especially in everyday, physical situations:

Ζεσταίνω το σίδερο. – I heat up the iron.
Ζέστανε το φαγητό. – Warm up the food.

Θερμαίνω is more formal / technical, often used in scientific or technical language:

Το σύστημα θερμαίνει το νερό. – The system heats the water.

So in a domestic, everyday context (preparing clothes, warming food, etc.), ζεσταίνω is the natural choice.

Why are ζεσταίνω and σιδερώνω in the present tense, not with θα for the future?

Here they describe immediate or planned actions closely tied to the interview. In Greek, you can use the simple present to talk about:

Actions happening right now
- I’m now heating the iron and ironing my shirt (as we speak).
Very near-future plans you’re about to carry out
- So I (now) go and heat up the iron and iron my shirt.

If you want to stress the future more explicitly, you can say:

…οπότε θα ζεστάνω το σίδερο και θα σιδερώσω το πουκάμισό μου.

That sounds more like:

…so I will heat up the iron and I will iron my shirt (at some point in the future).

Both versions are correct; the present gives a more immediate, “I’m doing this now / as a next step” feeling.

What is the difference between ζεσταίνω and ζεσταίνομαι?

They are active vs. passive/reflexive:

ζεσταίνω = I warm / heat (something)
- Ζεσταίνω το σίδερο. – I heat up the iron.
ζεσταίνομαι = I get warm / I’m being warmed / I feel warm
- Ζεσταίνομαι. – I’m getting warm / I’m hot (from heat).
- Το δωμάτιο ζεσταίνεται. – The room is getting warm.

So in your sentence, the iron is the object that you heat → ζεσταίνω το σίδερο.

What is the relationship between σίδερο, σιδερώνω, and σιδέρωμα?

They are related forms from the same root:

το σίδερο – the iron (the appliance; also “iron” the metal, depending on context)
σιδερώνω – to iron (clothes)
- Σιδερώνω το πουκάμισο. – I’m ironing the shirt.
το σιδέρωμα – the ironing (the activity, noun)
- Το σιδέρωμα είναι βαρετό. – Ironing is boring.

So the sentence literally says:
…ζεσταίνω το σίδερο και σιδερώνω το πουκάμισό μου.
…I warm up the iron and iron my shirt.

Why is there an accent on the last syllable in το πουκάμισό μου? I thought the word was πουκάμισο.

The basic word is:

το πουκάμισο – shirt
(accent on κά, the third syllable from the end)

When you add an enclitic pronoun like μου (my), the stress pattern changes because the whole thing is treated as one prosodic unit. Greek has a rule: the stress must fall on one of the last three syllables of the whole group.

πουκάμισο: που – κά – μι – σο
Stress: πουΚΑμισο → 3rd from end → OK.
πουκάμισο μου: που – κά – μι – σο – μου
If we kept the stress on κά, it would now be 4th from the end, which is not allowed.

So the stress moves closer to the end, and in practice it lands on the last syllable of the main word:

πουκάμισό μου (stress on -σό)

This shift happens whenever a word accented on the antepenultimate (like πουκάμισο, άνθρωπος, τηλέφωνο) is followed by an enclitic (μου, σου, του etc.):

ο άνθρωπος → ο άνθρωπός μου
το τηλέφωνο → το τηλέφωνό μου
το πουκάμισο → το πουκάμισό μου

Do all words change accent like πουκάμισο → πουκάμισό μου when I add μου?

No, only some do. The important point is where the stress originally is.

If the word is stressed on the antepenultimate (3rd from the end), like πουκάμισο, άνθρωπος, τηλέφωνο, then with μου/σου/του the stress moves closer to the end:
- πουκάμισο → πουκάμισό μου
- άνθρωπος → άνθρωπός μου
- τηλέφωνο → τηλέφωνό μου
If the word is stressed on the penultimate (2nd from the end), the stress usually stays where it is:
- βιβλίο → βιβλίο μου
- πατέρας → πατέρας μου

So the accent change is not “for all words”, but specifically for those originally accented too far from the end once you attach an enclitic.

Could I drop μου and just say σιδερώνω το πουκάμισο?

Grammatically, yes:

Σιδερώνω το πουκάμισο. – I iron the shirt.
Σιδερώνω το πουκάμισό μου. – I iron my shirt.

However, in the context of preparing for your own interview, το πουκάμισό μου sounds more natural and informative: it clarifies that it’s your shirt, not, say, your roommate’s.

So adding μου here is natural and idiomatic.

What gender is συνέντευξη and what article does it take?

Συνέντευξη is feminine.

η συνέντευξη – the interview
της συνέντευξης – of the interview (genitive)
τις συνεντεύξεις – the interviews (plural accusative)

In your sentence, it appears without an article (see earlier question), but if you used one, it would be:

Αύριο έχω μια συνέντευξη.
Αύριο έχω τη συνέντευξη για τη δουλειά. – I have the (specific) job interview tomorrow.

Is the whole sentence natural, everyday Greek?

Yes, it is completely natural and sounds like something a native speaker would say in everyday conversation:

Αύριο έχω συνέντευξη, οπότε ζεσταίνω το σίδερο και σιδερώνω το πουκάμισό μου.

You could also hear slight variations like:

…οπότε θα ζεστάνω το σίδερο και θα σιδερώσω το πουκάμισό μου.
…οπότε ζεσταίνω το σίδερο για να σιδερώσω το πουκάμισό μου.

But your original version is perfectly idiomatic.