Ο τόκος πληρώνεται κάθε μήνα.

Ο is the masculine singular definite article, equivalent to the in English.

So:

• ο τόκος = the interest

Greek usually uses the definite article more regularly than English does, especially with nouns that are specific or understood from context.

Here, τόκος means interest in the financial sense, not curiosity or personal interest.

So in a banking or loan context:

• ο τόκος = the interest
• οι τόκοι = the interest payments / the interest amounts or interests, depending on context

This is a useful word to distinguish from English, where interest can have more than one meaning.

Because πληρώνεται is a passive-form verb in Greek.

It comes from the verb πληρώνω = I pay.

Compare:

• πληρώνω = I pay
• πληρώνεται = it is paid / he-she-it pays itself, depending on context

In this sentence, the natural meaning is passive:

• Ο τόκος πληρώνεται κάθε μήνα.
• The interest is paid every month.

This is very common in Greek: the passive voice is often formed with endings like -μαι, -σαι, -ται in the present tense.

Πληρώνεται is 3rd person singular, present tense, passive voice.

That means it matches ο τόκος, which is also singular.

A rough breakdown:

• πληρών- = verb stem
• -εται = present passive, 3rd person singular

So literally it means:

• it is paid

because the subject is ο τόκος.

Κάθε means every / each.

After κάθε, the noun usually appears in the accusative singular.

So:

• dictionary form: ο μήνας = the month
• accusative singular: τον μήνα = the month
• after κάθε: κάθε μήνα = every month

So μήνα is accusative singular, not nominative.

This is a very common pattern:

• κάθε μέρα = every day
• κάθε εβδομάδα = every week
• κάθε χρόνο = every year
• κάθε μήνα = every month

It can mean every month or each month. In most contexts, the difference is not important.

So:

• Ο τόκος πληρώνεται κάθε μήνα.
• The interest is paid every month.
• The interest is paid each month.

Both are good translations.

Greek word order is often more flexible than English word order.

The neutral order here is:

• Ο τόκος πληρώνεται κάθε μήνα.

But you could also hear:

• Κάθε μήνα πληρώνεται ο τόκος.

This puts more emphasis on every month.

Because Greek uses endings and articles to show grammatical relationships, word order can shift more easily than in English. Still, the original sentence is the most straightforward and neutral version.

You know this from both the article + noun form and the verb agreement.

• ο τόκος is in the nominative singular, which is the usual subject form.
• πληρώνεται is 3rd person singular, so it matches ο τόκος.

So the sentence structure is:

• subject: ο τόκος
• verb: πληρώνεται
• time expression: κάθε μήνα

That is why the meaning is The interest is paid every month, not Someone pays the interest every month.

Yes, but the meaning would change.

• Ο τόκος πληρώνεται κάθε μήνα. = The interest is paid every month.
• Ο τόκος πληρώνει... would mean something like The interest pays..., which usually does not make sense in this context.

So the passive form πληρώνεται is the correct one here because the interest is the thing receiving the action.

The verb would also need to become plural.

Compare:

• Ο τόκος πληρώνεται κάθε μήνα. = The interest is paid every month.
• Οι τόκοι πληρώνονται κάθε μήνα. = The interest payments / the interests are paid every month.

Changes:

• ο → οι
• τόκος → τόκοι
• πληρώνεται → πληρώνονται

Greek verbs must agree with the subject in number.

A simple pronunciation guide is:

• πληρώνεται ≈ plee-RO-ne-te

And the whole sentence:

• Ο τόκος πληρώνεται κάθε μήνα.
• ≈ o TO-kos plee-RO-ne-te KA-the MEE-na

A few notes:

• η sounds like ee
• ω sounds like o
• αι in κάθε is pronounced like e
• the stress matters:
  • τόκος
  • πληρώνεται
  • κάθε
  • μήνα

It is completely normal and natural Greek, especially in financial, administrative, or banking contexts.

It sounds a bit more formal because of the topic, but the grammar itself is standard everyday Modern Greek:

• Ο τόκος = normal financial vocabulary
• πληρώνεται = normal passive construction
• κάθε μήνα = very common time expression

So it is not old-fashioned or unusually formal grammar.