Στην εκδήλωση ενδιαφέροντος γράφω τη φυλή του σκύλου: ημίαιμος.

Στην is the usual contraction of σε + την.

• σε = in / at / to
• την = the feminine singular definite article in the accusative

So στην εκδήλωση means in the event / in the declaration / on the form, depending on context.

This contraction is extremely common in Modern Greek:

• σε + το → στο
• σε + την → στη(ν)

Here the -ν is kept because the next word, εκδήλωση, begins with a vowel.

Because the preposition σε in Modern Greek normally takes the accusative.

The base noun is:

• η εκδήλωση = the event / declaration

In the accusative singular, it becomes:

• την εκδήλωση

And with σε + την, you get:

• στην εκδήλωση

So this is a very standard preposition + accusative structure.

Because εκδήλωση ενδιαφέροντος is a fixed phrase meaning something like expression of interest.

Here:

• εκδήλωση = expression / declaration
• ενδιαφέροντος = of interest

So ενδιαφέροντος is in the genitive singular because it depends on εκδήλωση and means of interest.

This kind of noun + genitive pattern is very common in Greek:

• οδηγός χρήσης = user guide, literally guide of use
• κέντρο υγείας = health center, literally center of health

Yes, literally γράφω means I write, but in this context it can also mean:

• I write down
• I fill in
• I enter

So if someone is talking about completing a form, γράφω often means putting the required information into the appropriate field.

Grammar:

• γράφω = first person singular, present tense
• so it means I write / I am writing

Because φυλή is the direct object of γράφω: it is the thing being written.

Base noun:

• η φυλή = the breed

As a direct object, it goes into the accusative:

• τη φυλή or την φυλή

So:

• γράφω τη φυλή = I write the breed

Also, Greek uses the definite article much more often than English, so the breed is natural here even if English might sometimes sound less article-heavy.

Both are related, but in normal Modern Greek the final -ν of την is often dropped before certain consonants.

So:

• την φυλή is possible in careful or formal writing
• τη φυλή is very common and natural

Before φ, dropping the final -ν is normal, so τη φυλή sounds perfectly standard.

By contrast, in στην εκδήλωση, the -ν stays because εκδήλωση starts with a vowel.

Because this is the genitive form meaning of the dog.

Base noun:

• ο σκύλος = the dog

Genitive singular:

• του σκύλου = of the dog

So:

• η φυλή του σκύλου = the dog’s breed / the breed of the dog

This is the normal Greek way to express possession. Greek also usually keeps the article in these genitive phrases, so του σκύλου is exactly what you would expect.

Ημίαιμος means mixed-breed or mongrel when talking about an animal, especially a dog.

Grammatically, it is an adjective, but it can also be used on its own like a noun:

• ημίαιμος σκύλος = mixed-breed dog
• ο σκύλος είναι ημίαιμος = the dog is mixed-breed
• on a form, just ημίαιμος can stand alone as the entry

Its gender forms are:

• masculine: ημίαιμος
• feminine: ημίαιμη
• neuter: ημίαιμο

This is a very natural question.

After the colon, ημίαιμος is not really functioning as an adjective directly modifying φυλή. It is more like the actual value being entered in the form.

So the idea is closer to:

• γράφω τη φυλή του σκύλου: ημίαιμος
• I fill in the dog’s breed: mixed-breed

The understood reference is really the dog:

• ο σκύλος είναι ημίαιμος

That is why the masculine form ημίαιμος appears.

If you tried to make it agree directly with φυλή, the structure would feel different. In this sentence, the word after the colon is best understood as a form entry or label answer, not as a normal adjective attached to φυλή.

The colon introduces the exact thing being written in the field.

It works a bit like:

• Breed: mixed-breed

So the sentence has a form-filling or note-taking feel. The part before the colon sets up the category, and the part after the colon gives the actual entry.

Without the colon, the sentence would need a different structure to sound equally natural.

Both can be used, but they are a little different in tone.

• φυλή is more formal and standard
• ράτσα is very common in everyday speech

So on a form or in more official language, φυλή is a very natural choice.

Examples:

• Τι φυλή είναι ο σκύλος; = What breed is the dog?
• Τι ράτσα είναι ο σκύλος; = What breed is the dog?

Both are understandable, but φυλή fits better in something that sounds administrative or form-based, like this sentence.