Η αμοιβή πληρώνεται αύριο.

η is the definite article meaning the.
Here it is the feminine singular nominative form, because it goes with αμοιβή, which is a feminine singular noun.

So:

• η = the
• η αμοιβή = the payment / the fee / the compensation

αμοιβή is simply a noun whose grammatical gender is feminine. In Greek, nouns have gender, and the article has to match that gender.

The ending -ή often belongs to feminine nouns, so it is a useful clue, but it is not a universal rule for every word in the language. The safest habit is to learn a noun together with its article:

• η αμοιβή
• η πόλη
• η ζωή

That way you learn both the word and its gender at the same time.

πληρώνεται is the 3rd person singular present mediopassive form of πληρώνω.

In simple learner terms, it means:

• it is paid
• it gets paid
• sometimes it is being paid, depending on context

The ending -εται is a very common mediopassive ending in Modern Greek.

Because Greek, like English, can use the present tense for a scheduled or arranged future event when a time word makes the future meaning clear.

So αύριο already tells you the action happens tomorrow. That allows Greek to use the present form πληρώνεται.

This is similar to English sentences like:

• The train leaves tomorrow.
• The payment goes out tomorrow.

So the sentence does not mean present time just because the verb is present in form.

Yes. A very common alternative would be:

• Η αμοιβή θα πληρωθεί αύριο.

That sounds more explicitly future: The payment will be paid / will be made tomorrow.

The original sentence with πληρώνεται αύριο can sound more like a scheduled or expected arrangement. The version with θα πληρωθεί is often the more straightforward way to express a one-time future event.

Yes, it is functioning as a passive form here.

In an active sentence, you would focus on the person or thing doing the paying.
In this sentence, the focus is on η αμοιβή, the thing receiving the action.

So Greek is structured like:

• The payment is paid
• more naturally in English: The payment is made / paid

Greek often uses these mediopassive forms where English may choose a passive or a slightly different wording.

It is not stated in this sentence. Greek often leaves that out if it is obvious or not important.

If you want to include the agent, you can add από:

• Η αμοιβή πληρώνεται από την εταιρεία αύριο.
• The payment is paid by the company tomorrow.

So the sentence as given focuses only on the payment itself and the time.

Yes, you can move it. Greek word order is more flexible than English word order.

The version given:

• Η αμοιβή πληρώνεται αύριο.

is perfectly natural. But you could also say:

• Αύριο πληρώνεται η αμοιβή.

That puts more emphasis on tomorrow.

The meaning stays basically the same; the difference is mostly one of emphasis and information flow.

αύριο is pronounced roughly AV-rio.

A useful rule:

• αυ sounds like av before a voiced sound or a vowel
• αυ sounds like af before a voiceless sound

Here, αυ comes before ρ, so it is pronounced av.

So:

• αύριο ≈ AV-rio

Also note that the accent mark shows the stressed syllable: ΑΥριο.

In Modern Greek, the accent mark shows which syllable is stressed.

So in this sentence:

• αμοιβή → stress on the last syllable
• πληρώνεται → stress on ρώ
• αύριο → stress on the first syllable

This is important because stress is part of the correct pronunciation of the word.

Because in a passive sentence, the thing affected by the action becomes the grammatical subject.

Here:

• η αμοιβή is in the nominative
• the verb πληρώνεται is 3rd person singular
• they match each other grammatically

So even though the payment is not doing the paying in a real-world sense, it is still the subject of the sentence in grammar terms.

Usually, with a specific noun like this, Greek normally keeps the article.

So:

• Η αμοιβή πληρώνεται αύριο. = natural

Without the article:

• Αμοιβή πληρώνεται αύριο.

this would usually sound unnatural or incomplete in ordinary Greek unless there were some special context, like a heading, a notice, or a very compressed style.

Greek uses the definite article more often than English does, so learners should get used to seeing it frequently.