Η μεσίτρια είπε ότι τα κοινόχρηστα πληρώνονται στην αρχή κάθε μήνα.

Η μεσίτρια means the female real-estate agent / broker.

• η = the for feminine singular nouns
• μεσίτρια = female agent/broker

Greek often marks grammatical gender clearly. Here the speaker is referring to a woman, so the feminine form μεσίτρια is used. The masculine form would be ο μεσίτης.

είπε is the aorist form of λέω (to say / tell), and here it means said.

So:

• λέω = I say
• είπε = he/she said

In this sentence, Η μεσίτρια είπε ότι... means The agent said that...

The aorist is very commonly used in Greek for a completed past action, like simple past in English.

ότι means that and introduces a subordinate clause.

So:

• Η μεσίτρια είπε = The agent said
• ότι τα κοινόχρηστα πληρώνονται... = that the common charges are paid...

Just like in English, that can connect what someone said to the content of the statement.

τα κοινόχρηστα usually means the common expenses / shared building charges / maintenance fees.

Literally, the word comes from the idea of shared-use things in a building. In real life, it often refers to charges for things like:

• cleaning common areas
• elevator maintenance
• lighting in shared spaces
• heating in some buildings
• other apartment-building shared costs

It is very common in housing-related Greek.

Because in Greek, κοινόχρηστα is often used as a substantivized adjective—that is, an adjective functioning like a noun.

Literally, κοινόχρηστα is related to common/shared-use, but in everyday Greek it stands on its own and means the common charges/fees.

This is normal in Greek. English does something similar sometimes, though less often.

πληρώνονται is the present mediopassive, 3rd person plural of πληρώνω (to pay).

So it means:

• they are paid
• or in more natural English here: they get paid / are payable

Breakdown:

• πληρώνω = I pay
• πληρώνονται = they are paid

Because τα κοινόχρηστα is plural, the verb is plural too.

It is grammatically a passive/mediopassive form, but in everyday use it often expresses a general fact or rule.

So τα κοινόχρηστα πληρώνονται στην αρχή κάθε μήνα can be understood as:

• the common charges are paid at the beginning of each month
• the common charges get paid at the beginning of each month
• you pay the common charges at the beginning of each month

English often prefers a more natural phrasing like The common charges are paid at the beginning of each month or even Common charges are due at the beginning of each month, depending on context.

στην is a contraction of σε + την.

• σε = in / at / to
• την = the (feminine accusative singular)

So:

• σε την αρχή becomes στην αρχή

This contraction is standard and very common in modern Greek.

στην αρχή means at the beginning.

• αρχή = beginning
• after σε (at/in/to), the noun appears with the article in the accusative: στην αρχή

This is a fixed, very common expression:

• στην αρχή = at the beginning
• στο τέλος = at the end

κάθε μήνα is the normal way to say every month / each month.

• κάθε = every / each
• μήνα = month (accusative singular)

After κάθε, Greek usually uses a singular noun without the article:

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

So στην αρχή κάθε μήνα means at the beginning of each month.

In the phrase κάθε μήνα, the noun after κάθε is commonly in the accusative singular.

This is just the normal pattern:

• κάθε χρόνο = every year
• κάθε φορά = every time
• κάθε μήνα = every month

So even though English uses of each month, Greek expresses it with κάθε + accusative.

Yes. Greek word order is more flexible than English, although the original sentence is very natural.

Original:

• Η μεσίτρια είπε ότι τα κοινόχρηστα πληρώνονται στην αρχή κάθε μήνα.

You could also hear:

• Η μεσίτρια είπε ότι στην αρχή κάθε μήνα πληρώνονται τα κοινόχρηστα.

Both are grammatical. The difference is mostly one of emphasis:

• τα κοινόχρηστα earlier = focus on what is paid
• στην αρχή κάθε μήνα earlier = focus on when they are paid

Yes, learners often notice this.

They are different:

• ότι = that
• ό,τι = whatever / anything that

In this sentence, it is definitely ότι because it introduces reported speech:

• είπε ότι... = said that...

So here there is no meaning of whatever.

Yes—several very useful patterns appear here:

• X είπε ότι... = X said that...
• πληρώνονται = are paid / get paid
• στην αρχή = at the beginning
• κάθε + singular noun = every + noun

So you can build many similar sentences:

• Είπε ότι το ενοίκιο πληρώνεται στην αρχή κάθε μήνα.
  He/She said that the rent is paid at the beginning of each month.

• Μου είπε ότι τα μαθήματα αρχίζουν κάθε Δευτέρα.
  He/She told me that the lessons start every Monday.

This makes the sentence a very good model for everyday Greek.