Learn Hardcore Greek: Αν χαθεί η λίστα, κανείς δεν θα ξέρει ποιος συμμετέχει στην οργάνωση. - If the list is lost, no one will know who participates in the organization.

χάνομαι = I get lost / I am lost
να χαθώ = (that) I get lost → 1st person singular aorist subjunctive
να χαθεί = (that) it gets lost → 3rd person singular aorist subjunctive
In this sentence the να is not written, because αν (if) already triggers the same subjunctive form:
- Αν χαθεί η λίστα = If the list (should) get lost / If the list is lost

We use the aorist subjunctive after αν for a future, one-time possibility: a single event of the list getting lost.

Why not use χάσει instead of χαθεί?

Χάσει is the aorist subjunctive of the active verb χάνω (to lose something):

να χάσω τη λίστα = (that) I lose the list
να χάσει τη λίστα = (that) he/she loses the list

If you said:

Αν χάσει τη λίστα…
that would mean If someone loses the list… (with an implied person doing the losing).

With Αν χαθεί η λίστα…, the focus is on the list itself:

Αν χαθεί η λίστα = If the list gets lost / If the list is lost
(the cause or person who lost it is not important)

Why is αν used and not εάν? Do they mean the same thing?

Yes, αν and εάν mean the same: if.

εάν is the older / more formal form.
In everyday modern Greek, people normally use the short form αν.

So:

Αν χαθεί η λίστα…
Εάν χαθεί η λίστα…

are equivalent; αν just sounds more natural in normal speech.

Is χαθεί a future tense? In English we say “if the list is lost (in the future)…”

Grammatically, χαθεί is not future; it is aorist subjunctive.
However, in Greek, with αν + subjunctive, we usually talk about future or hypothetical situations.

Pattern:

Αν
- subjunctive (here: χαθεί) → future / possible condition
θα
- future / simple form (here: θα ξέρει) → future result

So:

Αν χαθεί η λίστα, κανείς δεν θα ξέρει…
literally: If the list (should) get lost, no one will know…

Greek does not use a future tense in the αν-clause; it uses subjunctive instead.

What does κανείς δεν mean? Why is there both κανείς and δεν?

Κανείς is an indefinite pronoun. With a negation (δεν / μην), it means no one / nobody.

κανείς δεν θα ξέρει = no one will know / nobody will know

Greek normally uses a “double negative”:

κανείς δεν ξέρει = nobody knows
δεν λέω τίποτα = I say nothing
δεν πήγε πουθενά = he/she didn’t go anywhere

Without δεν, κανείς can mean someone / anyone in some contexts, especially in questions or conditionals:

Ξέρει κανείς; = Does anyone know?
Αν έρθει κανείς, πες μου. = If anyone comes, tell me.

In this sentence, κανείς δεν θα ξέρει clearly means no one will know.

Could we say κανένας instead of κανείς? What’s the difference?

Yes, you could say:

Κανένας δεν θα ξέρει ποιος συμμετέχει…

The meaning is the same: no one will know.

Differences:

Κανείς is slightly more neutral / a bit more formal.
Κανένας is more colloquial and also used very often.

In negative sentences:

κανείς = κανένας → nobody / no one

In positive questions/conditions (without δεν):

κανείς / κανένας can mean anyone / someone.

Why is it θα ξέρει and not something like θα μάθει or θα γνωρίζει?

All three verbs exist, but they have different nuances:

ξέρω = to know (have knowledge)
- κανείς δεν θα ξέρει = no one will know (no one will have that information)
μαθαίνω = to learn / to find out
- κανείς δεν θα μάθει = no one will find out (no one will ever learn this fact)
γνωρίζω = to know / to be acquainted with (more formal)
- κανείς δεν θα γνωρίζει = no one will be aware of / be acquainted with

In this sentence, θα ξέρει focuses on possessing the information about who participates.
Θα μάθει would sound more like “no one will ever find out” (the process of discovering).

Why is it ποιος συμμετέχει and not ποιον συμμετέχει?

Ποιος here is the subject of the verb συμμετέχει:

ποιος συμμετέχει = who participates

Because it is the subject, it must be in the nominative case: ποιος.

If ποιον were used, it would be object case (accusative), which doesn’t fit this structure.
Compare:

Ποιος συμμετέχει; = Who participates? (subject)
Ποιον βλέπεις; = Whom do you see? (object)

So in this sentence:

κανείς δεν θα ξέρει ποιος συμμετέχει
literally: no one will know who is participating
→ ποιος = the one who participates (subject).

Why is συμμετέχει in the present tense, not a future like θα συμμετέχει?

Συμμετέχει is present tense, but it expresses a general or current state: the people who are (the) participants / are involved.

The structure is:

Future knowing: δεν θα ξέρει (will not know)
About a relatively stable fact: ποιος συμμετέχει (who participates / is part of it)

So the idea is:

…κανείς δεν θα ξέρει ποιος συμμετέχει στην οργάνωση.
→ no one will know who (the people that) belong / are involved in the organization are.

If you said ποιος θα συμμετέχει, you would talk more about who will participate (in the future) in some event or activity, not about membership/ongoing involvement.

What is the difference between συμμετέχει and παίρνει μέρος?

Both can mean to participate, and in many contexts they are interchangeable:

συμμετέχω σε κάτι = I participate in something
παίρνω μέρος σε κάτι = I take part in something

Nuances:

συμμετέχω is a bit more formal / standard.
παίρνω μέρος is very common in everyday speech.

In this sentence, you could also say:

…ποιος παίρνει μέρος στην οργάνωση.

but συμμετέχει sounds very natural and slightly more formal or neutral in tone.

What exactly is στην? How is it formed?

Στην is the combination of the preposition σε and the feminine definite article την:

σε
- την → στην

So:

στην οργάνωση = σε την οργάνωση = in the organization

This contraction is very common:

σε + τον → στον (e.g. στον φίλο μου = to my friend)
σε + το → στο (e.g. στο σπίτι = at home)
σε + τους → στους
σε + τις → στις

Why is it στην οργάνωση and not something like της οργάνωσης?

Greek uses the preposition σε + accusative very often for location or membership / belonging to a group:

συμμετέχω στην οργάνωση = I participate in the organization
δουλεύω στην εταιρεία = I work at the company
είμαι στην ομάδα = I am on the team

Της οργάνωσης (genitive) would usually mean of the organization, e.g.:

τα μέλη της οργάνωσης = the members of the organization

Here the verb συμμετέχω takes σε + accusative, so we need στην οργάνωση.

Can the word order change? For example, can we say Αν η λίστα χαθεί or κανείς δεν θα ξέρει στην οργάνωση ποιος συμμετέχει?

Yes, Greek word order is quite flexible, as long as it stays clear and natural.

In the first clause:
- Αν χαθεί η λίστα
- Αν η λίστα χαθεί
Both are correct and mean the same thing.
The original order (χαθεί η λίστα) is very common, especially with short clauses and passive verbs.
In the second clause, you could technically move parts around, but not all options sound equally natural. For example:
- Κανείς δεν θα ξέρει ποιος συμμετέχει στην οργάνωση. ✔️ natural
- Κανείς δεν θα ξέρει στην οργάνωση ποιος συμμετέχει. ✅ grammatically possible, but sounds a bit heavier; emphasis shifts slightly.

The original sentence is the most natural and neutral word order.