Learn Hardcore Greek: Στην αστυνομία η υπάλληλος μου δίνει οδηγίες πώς να αλλάξω την ταυτότητά μου και το διαβατήριό μου. - At the police station the employee female gives me instructions on how to change my ID card and my passport.

Literally it’s “in/at the police”, which in natural English is “at the police station” or “at the police” (as an institution). In modern Greek, σε + article is almost always merged in writing:

σε την → στην
σε το → στο, etc.

Does αστυνομία mean “police station” or “the police” as an institution?

Αστυνομία is literally “police” as an institution/body (feminine singular).

Depending on context, στην αστυνομία can mean:

at the police (office/department) – roughly “at the police station”
at the police (as an institution) – “with the police”

If you want to be more precise about building, you can say:

στο αστυνομικό τμήμα = at the police station / police department
στη διεύθυνση αστυνομίας = at the police directorate (more official)

Why is it η υπάλληλος if υπάλληλος ends in -ος, which I thought was masculine?

Υπάλληλος is a common-gender noun: its form is the same for masculine and feminine, and the article tells you the gender.

ο υπάλληλος = the (male) employee/clerk
η υπάλληλος = the (female) employee/clerk

So the -ος ending here doesn’t uniquely mark masculine; the article ο / η does the job. In the sentence, η υπάλληλος clearly indicates a female employee.

What is the difference between υπάλληλος and αστυνομικός?

υπάλληλος = employee, clerk (generic). In this context, it’s probably a civil servant / counter clerk working at the police.
αστυνομικός = police officer (literally “policeman/policewoman”).

So:

η υπάλληλος στην αστυνομία = the clerk/employee at the police
η αστυνομικός / ο αστυνομικός = the police officer

Why is it μου δίνει and not δίνει μου? Where does the pronoun usually go?

Μου here is an unstressed object pronoun (to me). In standard Greek:

With a simple verb form, the weak pronoun usually comes before the verb:
- μου δίνει = she gives me
- σου λέω = I tell you
It normally goes after the verb only in certain cases (imperatives, some infinitive-like forms, participles), for example:
- δώσε μου = give me
- πες μου = tell me

So in a neutral declarative sentence like this, μου δίνει is the normal order.

What exactly does οδηγίες mean, and why is it plural?

Οδηγία = instruction, directive, guideline.
Οδηγίες (plural) = instructions, directions.

Greek tends to use the plural for this idea, just like English often says “instructions” or “directions” in the plural:

μου δίνει οδηγίες = she gives me instructions / she tells me what to do

You can say μία οδηγία for a single instruction, but in this context, plural is the natural choice.

How does πώς να αλλάξω work grammatically? Is it like “how to change”?

Yes, πώς να αλλάξω corresponds closely to “how to change” / “how I should change”.

Key points:

Modern Greek doesn’t use a real infinitive like English to change.
Instead, it uses να
- a verb in the subjunctive:
  - να αλλάξω ≈ “(for me) to change / that I change”

With πώς (how) in front:

πώς να αλλάξω… = how (I am) to change… / how I should change…

So οδηγίες πώς να αλλάξω… = instructions on how to change…

Why is it αλλάξω and not αλλάζω? What’s the difference?

Both come from the verb αλλάζω (to change), but they differ in aspect:

αλλάζω (present) – ongoing, repeated, or general action
- πώς να αλλάζω ≈ how I (should) be changing (habitually/continuously)
αλλάξω (aorist subjunctive) – single, complete action
- πώς να αλλάξω ≈ how I (should) change (it) once / carry out the change

Here we are talking about performing one change to your ID card and passport, so the aorist subjunctive (αλλάξω) is the natural choice.

Why is it την ταυτότητά μου with the accent on -τά? I thought it was ταυτότητα.

The basic form is:

ταυτότητα = identity card / ID card (stress on -τό-: ταυτότητα)

But when a word stressed on the third syllable from the end (like ταυτότητα) is immediately followed by an enclitic pronoun such as μου, Greek accent rules force the stress closer to the end of the group.

So:

η ταυτότητα → την ταυτότητά μου

The stress in writing moves to the last syllable of ταυτότητα (-τά) when you add μου. This is a regular accent rule for such words before enclitics; you’re still saying “my ID card”.

Why do we also see το διαβατήριό μου with the accent on -ριό?

Same phenomenon as with ταυτότητά μου:

Base form: διαβατήριο = passport (stress on -τή-: διαβατήριο)
With enclitic μου: το διαβατήριό μου

Because διαβατήριο is also stressed on the third syllable from the end, when an enclitic like μου follows, the accent shifts to the last syllable of the noun (-ριό) to obey Greek accent rules.

So you get:

το διαβατήριό μου = my passport

Why do we use την and το here? What case are την ταυτότητά μου and το διαβατήριό μου in?

Την and το are definite articles in the accusative singular:

την = the (feminine, accusative singular)
το = the (neuter, accusative singular)

They mark direct objects of the verb αλλάξω:

να αλλάξω την ταυτότητά μου = to change my ID card
(να αλλάξω) το διαβατήριό μου = (to change) my passport

So both ταυτότητα (feminine) and διαβατήριο (neuter) appear in the accusative as objects of αλλάξω, and their articles agree in gender and case.

Do we really need to repeat μου twice? Could we say την ταυτότητά και το διαβατήριό μου?

Natural options are:

την ταυτότητά μου και το διαβατήριό μου – fully explicit (and very common).
την ταυτότητα και το διαβατήριό μου – possible, but feels like only the passport is clearly “mine”, and the first noun is a bit “dangling”.

Greek typically attaches μου to each noun you clearly want to mark as possessed:

το σπίτι μου και το αυτοκίνητό μου = my house and my car

You can sometimes economize, especially in speech, but:

την ταυτότητά μου και το διαβατήριό μου is the clearest and most standard.

Saying την ταυτότητά και το διαβατήριό μου (without μου after ταυτότητά) is unusual and feels incomplete/wrong.

Can we change the word order and say Η υπάλληλος στην αστυνομία μου δίνει οδηγίες…? Does it change the meaning?

Yes, you can say:

Η υπάλληλος στην αστυνομία μου δίνει οδηγίες…

Both versions are grammatically correct:

Στην αστυνομία η υπάλληλος μου δίνει οδηγίες…
– Fronts στην αστυνομία for topicalization/emphasis: “At the police station, the clerk gives me instructions…”
Η υπάλληλος στην αστυνομία μου δίνει οδηγίες…
– Starts with η υπάλληλος and then specifies στην αστυνομία: “The employee at the police (station) gives me instructions…”

The basic meaning is the same, but the focus shifts slightly depending on what you put first.

Is Στην αστυνομία the most natural way to say “At the police station”, or is there a more specific expression?

Στην αστυνομία is very common and perfectly natural in everyday speech, especially when context makes it clear you’re talking about visiting the police office / station.

If you want to be more explicit about “police station”, you can say:

στο αστυνομικό τμήμα – at the police station / police department
στο τμήμα – colloquial, literally “at the department”, often understood as “at the police station” in context

So your sentence is fine as it stands, but στο αστυνομικό τμήμα would make “police station” very clear.