Η φωτογραφική έκθεση είναι σωστή.

Η is the definite article for a feminine singular noun in the nominative case. It corresponds to the in English.

In this sentence, the noun is έκθεση, which is feminine singular, so the article is η:

• η έκθεση = the exhibition

Greek uses definite articles more often than English, so learners will see them a lot.

You usually learn the gender together with the noun, but the ending can often give you a clue. Έκθεση ends in -η, which is a very common feminine ending in Greek.

So:

• η έκθεση = feminine singular

Because it is feminine, any adjective describing it must also be in the feminine singular form.

Because it agrees with έκθεση.

In Greek, adjectives change form to match the noun they describe in:

• gender
• number
• case

Here, έκθεση is feminine singular nominative, so the adjective also has to be feminine singular nominative:

• masculine: φωτογραφικός
• feminine: φωτογραφική
• neuter: φωτογραφικό

So φωτογραφική έκθεση is an adjective + noun combination where both words match grammatically.

For the same reason: it refers to έκθεση, so it must agree with it.

Even though σωστή comes after είναι, it is still describing the noun. This is called a predicate adjective.

So Greek still makes it match:

• η έκθεση είναι σωστή
• literally: the exhibition is correct/right/proper

Compare the forms:

• masculine: σωστός
• feminine: σωστή
• neuter: σωστό

They are both adjectives, but they do different jobs.

• φωτογραφική directly modifies the noun:
  η φωτογραφική έκθεση = the photographic exhibition
• σωστή comes after είναι and tells you something about the subject:
  είναι σωστή = is correct/right/proper

So:

• φωτογραφική is an attributive adjective
• σωστή is a predicate adjective

Είναι is the 3rd person singular present tense of είμαι, meaning to be.

So:

• είμαι = I am
• είσαι = you are
• είναι = he/she/it is

In this sentence:

• Η φωτογραφική έκθεση είναι σωστή.
• The photographic exhibition is correct.

Yes, Greek word order is more flexible than English because the endings show grammatical relationships more clearly.

The neutral, standard order here is:

• Η φωτογραφική έκθεση είναι σωστή.

But other orders may be possible for emphasis, for example:

• Σωστή είναι η φωτογραφική έκθεση.

That would sound more marked or emphatic, something like:

• It is the photographic exhibition that is correct.

For learners, it is best to stick with the standard order first.

The accent mark shows which syllable is stressed in pronunciation.

For example:

• φωτογραφική → stress on the last syllable
• έκθεση → stress on the first syllable
• είναι → stress on the first syllable
• σωστή → stress on the last syllable

Stress matters in Greek, so the accent is an important part of the written word.

A rough pronunciation is:

ee fo-to-gra-fee-KI EK-the-see EH-ne so-STI

A few useful notes:

• η sounds like ee
• θ sounds like th in think
• χ would sound like a harsher sound, but it does not appear here
• αι in είναι is pronounced e
• η / ι / υ / ει / οι often sound like ee in Modern Greek

Not necessarily. Depending on context, σωστός / σωστή / σωστό can mean:

• correct
• right
• proper
• appropriate

So είναι σωστή could mean different things depending on what was already being discussed. The grammar stays the same either way.

Normally, yes, if you mean the photographic exhibition.

• Η φωτογραφική έκθεση = the photographic exhibition

If you removed the article, you would get:

• Φωτογραφική έκθεση

That could work in special contexts, like a heading, label, or very general style, but in a normal full sentence the article is usually expected.

The subject of the sentence is in the nominative case:

• Η φωτογραφική έκθεση

Because it is the subject, both the article and the attributive adjective are nominative feminine singular.

The predicate adjective σωστή also appears in the nominative because it refers back to the subject after είναι.

So all the agreeing words here are:

• η — feminine singular nominative
• φωτογραφική — feminine singular nominative
• έκθεση — feminine singular nominative
• σωστή — feminine singular nominative