Learn Hardcore Greek: Η συνάντηση αύριο μάλλον θα ακυρωθεί αν έχει καταιγίδα. - Tomorrow’s meeting will probably be cancelled if there is a storm.

Be aware that μάλλον can also mean rather / instead in other contexts (e.g. Όχι καφέ, μάλλον τσάι. = Not coffee, rather tea.), but in front of a verb about the future or a guess, it almost always means probably.

Why is it θα ακυρωθεί and not something like θα ακυρώσει?

Θα ακυρωθεί is future passive:

ακυρώνω = I cancel (active)
ακυρώνομαι = I am cancelled (middle/passive form)
θα ακυρωθεί = it will be cancelled (3rd person singular, future passive)

Because the English sentence is “the meeting will be cancelled” (passive), Greek also uses the passive.

If you wanted an active version (someone cancels it), you’d say for example:

Θα ακυρώσουμε τη συνάντηση.
We will cancel the meeting.
Η διεύθυνση θα ακυρώσει τη συνάντηση.
Management will cancel the meeting.

Why do we say Η συνάντηση with the article Η? Could we just say Συνάντηση αύριο μάλλον θα ακυρωθεί…?

In Greek, definite articles (ο, η, το) are used much more often than in English.

Η συνάντηση = the meeting (feminine)
The article η marks the gender (feminine), number (singular), and case (nominative/subject).

Leaving the article out here (Συνάντηση αύριο μάλλον θα ακυρωθεί…) sounds unnatural and almost like a headline or a note on a schedule, not like normal spoken Greek.

So in normal speech/writing, you need:

Η συνάντηση αύριο μάλλον θα ακυρωθεί…
The meeting will probably be cancelled tomorrow…

Why is αύριο (tomorrow) placed after Η συνάντηση and before μάλλον? Can it move?

Greek word order is quite flexible. Αύριο is an adverb of time and can move around. All of these are possible:

Η συνάντηση αύριο μάλλον θα ακυρωθεί…
Αύριο η συνάντηση μάλλον θα ακυρωθεί…
Η συνάντηση μάλλον θα ακυρωθεί αύριο…

All three are grammatically correct; they just change the focus slightly:

Putting αύριο at the start (Αύριο…) emphasizes tomorrow.
Putting it near θα ακυρωθεί emphasizes when the cancellation will happen.

The version you have is very natural and neutral.

Why do we use αν έχει καταιγίδα (present έχει) for a future situation? Why not αν θα έχει καταιγίδα?

In Greek, after αν (if), you do not use θα for future reference.

You say:

Αν έχει καταιγίδα, η συνάντηση μάλλον θα ακυρωθεί.
If there is a storm, the meeting will probably be cancelled.

Not:

✗ Αν θα έχει καταιγίδα… (this is wrong or at least very unnatural)

So:

Main clause (future): uses θα → …μάλλον θα ακυρωθεί.
If-clause (introduced by αν): uses present → αν έχει καταιγίδα.

Even though you use the present tense in Greek, the meaning is future, because of αν and the context.

Is αν έχει καταιγίδα more like “if there is a storm” or “if there is going to be a storm”?

Literally it is “if it has a storm”, but idiomatically it corresponds to:

If there is a storm / if there’s going to be a storm.

Greek doesn’t need a special future form here. The present with αν plus the future in the main clause (θα ακυρωθεί) already gives the idea of a future condition:

Αν έχει καταιγίδα, η συνάντηση μάλλον θα ακυρωθεί.
→ If there’s a storm, the meeting will probably be cancelled.

Why is it έχει καταιγίδα and not είναι καταιγίδα?

For weather, Greek often uses έχει (it has) instead of είναι (it is). Some common patterns:

Έχει ήλιο. – It’s sunny. (Literally: It has sun.)
Έχει συννεφιά. – It’s cloudy. (It has cloudiness.)
Έχει αέρα. – It’s windy. (It has wind.)
Έχει καταιγίδα. – There is a storm / It’s stormy. (It has a storm.)

You do not say:

✗ Είναι καταιγίδα to mean It’s stormy.

You could say:

Έχει καταιγίδα. – There is a storm.
Θα έχει καταιγίδα. – There will be a storm.

What exactly is καταιγίδα? Is it just “rain”?

Καταιγίδα means storm, usually with heavy rain, often with thunder and lightning.

βροχή = rain
δυνατή βροχή = heavy rain
καταιγίδα = storm (more intense, often with thunder)

So:

αν έχει καταιγίδα = if there is a storm
Not just if it rains a bit.

Can I move μάλλον to a different position in the sentence?

Yes. Μάλλον is an adverb and is quite mobile. All of these are acceptable:

Η συνάντηση αύριο μάλλον θα ακυρωθεί αν έχει καταιγίδα.
Η συνάντηση αύριο θα ακυρωθεί μάλλον αν έχει καταιγίδα.
Η συνάντηση μάλλον αύριο θα ακυρωθεί αν έχει καταιγίδα.

The most common and natural positions are just before the verb phrase or right after the subject:

Η συνάντηση μάλλον θα ακυρωθεί αύριο…
Μάλλον η συνάντηση θα ακυρωθεί αύριο…

If you put μάλλον too far away from θα ακυρωθεί, it can sound slightly awkward, but it’s hard to make it completely wrong.

How is ακυρωθεί formed, and what’s the basic dictionary form?

The dictionary (infinitive-like) form you’ll find is:

ακυρώνω – to cancel

From this, you get:

παθητική φωνή (passive voice) stem: ακυρώνομαι – I am cancelled

The aorist passive stem is ακυρωθ-:

να ακυρωθεί – that it be cancelled / to be cancelled
θα ακυρωθεί – it will be cancelled

So ακυρωθεί is the aorist passive form, used here with θα to make the simple future passive.

Why is there no comma before αν έχει καταιγίδα in the Greek sentence?

In Greek, a comma before αν in this type of conditional sentence is optional:

Η συνάντηση αύριο μάλλον θα ακυρωθεί, αν έχει καταιγίδα.
Η συνάντηση αύριο μάλλον θα ακυρωθεί αν έχει καταιγίδα.

Both versions are acceptable. Many writers omit the comma when the sentence is short and clearly understood. Adding it can make the pause more explicit in writing, but it’s not required by a strict rule here.

How do you pronounce συνάντηση and where is the stress?

Συνάντηση is pronounced approximately:

see-NÁN-dee-see (IPA: /siˈna.ndisi/)

Details:

The stress is on the second syllable: -νά- → συνΆντηση.
The η at the end is pronounced like i (as in machine).
The ντ is like an English “nd” sound here.

Because of the final -η, συνάντηση is generally feminine, which is why you use η συνάντηση with the article η.