Η υπάλληλος στο δημαρχείο είπε ότι ο φόρος είναι μικρός, αλλά το παλιό χρέος πρέπει να πληρωθεί μέχρι την Παρασκευή.

υπάλληλος is one of those Greek nouns that can refer to either a man or a woman. The article shows the gender here:

• η υπάλληλος = the female employee / clerk
• ο υπάλληλος = the male employee / clerk

So even though the noun ends in -ος, which learners often associate with masculine nouns, it can also be feminine.

στο is a contraction of σε + το.

• σε = in / at / to
• το δημαρχείο = the town hall / city hall

So:

• στο δημαρχείο = at the town hall / in the town hall

This is very common in modern Greek:

• σε το → στο
• σε τη(ν) → στη(ν)

Also notice that after σε, modern Greek uses the accusative, not a separate dative case.

είπε is the aorist form of λέω and here it works like a simple past:

• λέει = he/she says
• είπε = he/she said

In this sentence, είπε reports a completed speaking event: the employee said something. Greek often uses the aorist where English uses the simple past for a single completed action.

ότι introduces a clause meaning that:

• είπε ότι... = she said that...

It is a very common way to introduce reported speech or reported statements.

In many cases, Greek can also use πως in a similar way:

• είπε ότι...
• είπε πως...

Both can mean said that... In a learner sentence like this, ότι is completely standard.

Because ο φόρος is the subject of είναι.

In ο φόρος είναι μικρός:

• ο φόρος = the tax → subject, so nominative
• μικρός = small → predicate adjective describing the subject

Greek keeps the subject in the nominative after είναι, just as English uses the normal subject form in the tax is small.

Because μικρός agrees with φόρος.

Greek adjectives agree with the noun they describe in:

• gender
• number
• case

Here:

• φόρος is masculine singular nominative
• so the adjective is also masculine singular nominative: μικρός

Compare:

• ο μικρός φόρος = the small tax
• η μικρή οφειλή = the small debt
• το μικρό χρέος = the small debt

Yes. αλλά is the normal word for but.

It connects two contrasting ideas:

• the tax is small
• but the old debt still must be paid

So its function is very close to English but.

This is a very common Greek structure.

• πρέπει = it is necessary / must
• να introduces the following verb
• πληρωθεί = be paid

So:

• πρέπει να πληρωθεί = must be paid

A useful way to understand it is:

• πρέπει is impersonal: it is necessary
• να + verb gives the action that is necessary

This pattern appears everywhere in Greek:

• πρέπει να φύγω = I must leave
• πρέπει να έρθει = he/she must come
• πρέπει να πληρωθεί = it must be paid

πληρωθεί is the aorist passive dependent form of πληρώνω.

You do not need to master the terminology immediately, but the key idea is:

• πληρώνω = I pay
• πληρώνομαι = I get paid / I am paid
• να πληρωθεί = to be paid

In this sentence, it is passive because the debt is not doing the paying; the debt is the thing that needs to be paid.

Greek uses this kind of form after να, θα, and some other particles instead of an infinitive.

Again, this is adjective agreement.

• χρέος is neuter singular
• so the article is το
• and the adjective is παλιό

So:

• το χρέος = the debt
• το παλιό χρέος = the old debt

Notice that χρέος is a neuter noun ending in -ος, which can surprise learners. Not every noun ending in -ος is masculine.

After μέχρι in expressions of time, Greek commonly uses the accusative, and Παρασκευή here behaves like a feminine noun with its article:

• η Παρασκευή = Friday
• την Παρασκευή = Friday, in the accusative

So:

• μέχρι την Παρασκευή = until Friday

Greek often uses the article with days of the week in these time expressions.

Word-for-word, it includes the article, yes, but in natural English you usually translate it simply as until Friday.

Greek uses articles more often than English in time expressions. So learners should not always translate the article directly.

Because Greek is using a passive idea: the old debt must be paid.

In that structure:

• το παλιό χρέος is the thing affected by the action
• but grammatically it becomes the subject of the passive verb phrase

This is the same as in English:

• They must pay the old debt → active
• The old debt must be paid → passive

Greek has chosen the passive version here.

Yes, Greek word order is more flexible than English because case endings and articles help show what each word is doing.

For example, the sentence could be rearranged for emphasis in some contexts, especially parts like:

• Ο φόρος είναι μικρός
• Μικρός είναι ο φόρος

Both can be grammatical, but the neutral, straightforward order in your sentence is very natural for learners to study.

Modern Greek does not use the infinitive the way English does. Instead, it usually uses:

• να + verb form

So where English says:

• must be paid

Greek says:

• πρέπει να πληρωθεί

This is one of the biggest structural differences between English and modern Greek.

It can be translated either way depending on context.

• δημαρχείο = the municipal building / town hall / city hall

The exact English choice depends on the place being described. Grammatically, though, it is just a neuter noun here after στο.