Η ταυτότητά σου είναι ληγμένη, οπότε δεν θεωρείται πια έγκυρο έγγραφο.

The basic noun is η ταυτότητα (identity / ID card), with the stress on -τό-.

When it is followed by an unstressed possessive like μου, σου, του, της, Greek often adds an extra written accent to show the new stress pattern:

• η ταυτότητα
• η ταυτότητά σου = your ID card

This happens because σου is an enclitic, and Greek spelling marks the extra stress shift. This is very common:

• το όνομά μου = my name
• η τσάντά σου = your bag
• η ταυτότητά σου = your ID card

So the extra accent is not changing the meaning; it is showing the correct pronunciation and stress.

Here, ταυτότητα means ID card / identity card, not the abstract idea of identity.

Greek η ταυτότητα can mean:

• identity in an abstract sense
• ID card / identification card in everyday use

In this sentence, because it is described as expired and as a document, it clearly means ID card.

Because ληγμένη agrees with η ταυτότητα, which is:

• feminine
• singular

So the adjective or participle must also be feminine singular:

• ο ληγμένος = masculine singular
• η ληγμένη = feminine singular
• το ληγμένο = neuter singular

Since ταυτότητα is feminine, Greek uses ληγμένη.

Ληγμένη means expired.

It comes from the verb λήγω, which means to expire / to come to an end.

You will often see it with things like:

• ληγμένο διαβατήριο = expired passport
• ληγμένη άδεια = expired permit
• ληγμένα τρόφιμα = expired food

So Η ταυτότητά σου είναι ληγμένη means Your ID card has expired / is expired.

Θεωρείται means is considered.

It is the passive form of θεωρώ:

• θεωρώ = I consider
• θεωρείται = it is considered

So:

• δεν θεωρείται πια έγκυρο έγγραφο = it is no longer considered a valid document

This is a very common structure in Greek for formal or official language.

Greek often leaves out words that are understood from context.

The subject of θεωρείται is still η ταυτότητά σου from the first part of the sentence:

• Η ταυτότητά σου είναι ληγμένη
• οπότε δεν θεωρείται πια έγκυρο έγγραφο

Literally:

• Your ID card is expired, so [it] is no longer considered a valid document.

Greek does not need to repeat αυτή or η ταυτότητά σου here, because the subject is already clear.

Because έγκυρο agrees with έγγραφο, not with ταυτότητα.

In the phrase:

• έγκυρο έγγραφο = valid document

the noun έγγραφο is:

• neuter
• singular

So the adjective must also be neuter singular:

• έγκυρος = masculine
• έγκυρη = feminine
• έγκυρο = neuter

Even though the thing being talked about is η ταυτότητα (feminine), the sentence says it is no longer considered a valid document, and document is neuter in Greek.

Έγκυρο means valid.

It is often used for:

• έγκυρο έγγραφο = valid document
• έγκυρη άδεια = valid permit/license
• έγκυρο εισιτήριο = valid ticket

It can also mean reliable / authoritative in some contexts, but here it clearly means legally valid.

Greek does not have an indefinite article like English a / an.

So:

• έγγραφο can mean document or a document
• έγκυρο έγγραφο = a valid document

Greek only has a definite article:

• ο, η, το = the

So if Greek wants to say a valid document, it usually just says έγκυρο έγγραφο without an article.

Πια here means anymore / no longer.

In negative sentences, it often gives the idea of not anymore:

• Δεν μένει εδώ πια. = He/She doesn’t live here anymore.
• Δεν δουλεύω εκεί πια. = I don’t work there anymore.
• Δεν θεωρείται πια έγκυρο έγγραφο. = It is no longer considered a valid document.

So πια adds the idea that this used to be true, but is not true now.

That is a natural word order in Greek.

• δεν θεωρείται πια έγκυρο έγγραφο

Literally:

• is not considered anymore a valid document

Greek adverbs like πια often go after the verb, especially in everyday speech and writing. It sounds natural there and modifies the whole idea of being considered valid.

Here οπότε means so / therefore / as a result.

In this sentence it connects cause and result:

• Η ταυτότητά σου είναι ληγμένη
• οπότε δεν θεωρείται πια έγκυρο έγγραφο

So the meaning is:

• Your ID card is expired, so it is no longer considered a valid document.

Depending on context, οπότε can also mean when, but not here.

Οπότε is very common and natural in both speech and writing. It is not especially slangy, but it is a bit more conversational than very formal connectors like:

• επομένως = therefore
• συνεπώς = consequently

So in this sentence, οπότε sounds normal and natural.

Yes, but the meaning is slightly different.

• δεν είναι πια έγκυρο έγγραφο = it is no longer a valid document
• δεν θεωρείται πια έγκυρο έγγραφο = it is no longer considered a valid document

The version with θεωρείται sounds a bit more official or legal, as if we are talking about status in the eyes of rules or authorities.

Yes, especially the second half sounds somewhat formal or official:

• δεν θεωρείται πια έγκυρο έγγραφο

That is the kind of wording you might see in:

• government notices
• official explanations
• administrative language

The first part, Η ταυτότητά σου είναι ληγμένη, is completely everyday Greek.

A very literal breakdown would be:

• Η = the
• ταυτότητά σου = your ID card
• είναι = is
• ληγμένη = expired
• οπότε = so / therefore
• δεν = not
• θεωρείται = is considered
• πια = anymore / any longer
• έγκυρο έγγραφο = valid document

So a near-literal translation is:

Your ID card is expired, so it is no longer considered a valid document.

A simple pronunciation guide is:

ee taf-to-TEE-TA soo EE-ne leegh-ME-nee, o-PO-te then the-o-REE-te PYA ENG-kee-ro EGH-gra-fo

A few useful notes:

• η / ι / υ all sound like ee
• γγ in έγγραφο sounds like a hard g sound
• θεωρείται has the stress on -ρεί-
• πια sounds like pya, almost one syllable for many speakers

Σου is the weak possessive form meaning your.

Historically and grammatically, it comes from the genitive form of the pronoun. In Modern Greek, learners usually just learn it as the normal possessive word:

• μου = my
• σου = your
• του / της = his / her
• μας = our
• σας = your
• τους = their

So η ταυτότητά σου literally works like the ID card of you, but in natural English it is just your ID card.