Learn Hardcore Greek: Η σύγκριση με τα παλιά μου κείμενα δείχνει μεγάλη διαφορά στο ύφος και στο λεξιλόγιο. - The comparison with my old texts shows a big difference in style and in vocabulary.

Η σύγκριση literally = “the comparison”, but very often in Greek this also functions like English “comparison” or “comparing” in a general sense.
Greek uses the definite article much more than English, especially with abstract nouns used as subjects.

If you omit it and say Σύγκριση με τα παλιά μου κείμενα δείχνει…, it sounds incomplete or like a headline/title. In normal sentences you’d almost always keep Η here.

Why is σύγκριση feminine, and how is it declined?

Nouns ending in -ση (from ancient -σις) are almost always feminine.

σύγκριση (comparison) is feminine and follows this pattern:

Nominative (subject): η σύγκριση – the comparison
Genitive: της σύγκρισης – of the comparison
Accusative: τη(ν) σύγκριση – the comparison (object)
Vocative: σύγκριση

Plural:

Nominative / Vocative: οι συγκρίσεις
Genitive: των συγκρίσεων
Accusative: τις συγκρίσεις

In your sentence, Η σύγκριση is nominative singular — it’s the subject of δείχνει.

Why is it με τα παλιά μου κείμενα? Which case is that, and does με always take that case?

με is the preposition “with”, and in modern Greek it almost always takes the accusative case.

τα παλιά μου κείμενα is accusative plural neuter:
- τα (article, acc. plural neuter)
- παλιά (adjective, acc. plural neuter)
- μου (possessive pronoun “my”, invariable)
- κείμενα (noun, acc. plural neuter)

So the structure is:

με + accusative → με τα παλιά μου κείμενα = with my old texts

Yes, with this meaning με takes the accusative in modern usage.

How does τα παλιά μου κείμενα work in terms of word order? Where do adjectives and possessives usually go?

The most neutral order is:

article + adjective + noun + possessive pronoun
τα παλιά κείμενα μου

In practice, both of these are very common and natural:

τα παλιά μου κείμενα
τα παλιά κείμενα μου

The possessive μου is an enclitic and can come right after the noun or after the adjective–noun group. All of these mean “my old texts”.

You can also change the word order for emphasis:

τα κείμενά μου τα παλιά – my texts, the old ones (emphasis on “old”)

But τα παλιά μου κείμενα is the straightforward, typical phrase learners should use.

What form is the verb δείχνει, and who/what is the subject of the sentence?

δείχνει comes from the verb δείχνω (“to show”).

Person: 3rd person
Number: singular
Tense: present
Mood: indicative

So δείχνει = “(he/she/it) shows” or “is showing”.

The subject is Η σύγκριση (“the comparison”). The core structure is:

Η σύγκριση … δείχνει μεγάλη διαφορά …
→ The comparison … shows a big difference …

Why is it μεγάλη διαφορά and not μεγάλο διαφορά?

Because adjectives must agree with the noun in gender, number, and case.

διαφορά is feminine singular nominative here.
The adjective from the base μεγάλος must therefore also be feminine singular nominative:
- μεγάλος (masculine)
- μεγάλη (feminine)
- μεγάλο (neuter)

So:

μεγάλη διαφορά = big/great difference (feminine–feminine)

μεγάλο διαφορά would be incorrect because μεγάλο is neuter, while διαφορά is feminine.

Why is there no word for “a” in δείχνει μεγάλη διαφορά? How do you say “a big difference” in Greek?

Modern Greek doesn’t use an indefinite article like English “a/an” in the same way.

Instead:

A bare noun (without article) often corresponds to English “a/an” or “some”:
- δείχνει μεγάλη διαφορά ≈ “shows a big difference”

There are forms ένας / μια / ένα that can function as an indefinite article, but they’re not used as routinely as “a/an” in English. You’d use them when you want to emphasize one single thing or introduce something specific:

δείχνει μια μεγάλη διαφορά – also possible, but it focuses more on one particular big difference.

Your sentence is natural and idiomatic as it stands; Greek often omits any article in this type of expression.

What exactly is στο in στο ύφος and στο λεξιλόγιο? Why not write σε το?

στο is a contraction of:

σε + το → στο

σε is a very common preposition meaning in / at / to, and το is the neuter singular definite article “the”.

So:

σε το ύφος → στο ύφος
σε το λεξιλόγιο → στο λεξιλόγιο

These contracted forms are standard and almost always used in speech and writing. Other common contractions:

σε + την → στην
σε + τους → στους
σε + τα → στα

Why is στο repeated in στο ύφος και στο λεξιλόγιο? Could I say στο ύφος και λεξιλόγιο instead?

In standard Greek, when you coordinate two nouns that each depend on the same preposition + article, it is normal and clearer to repeat the preposition+article:

στο ύφος και στο λεξιλόγιο
= in the style and in the vocabulary

If you say στο ύφος και λεξιλόγιο, it sounds incomplete or sloppy, especially in writing. You’re effectively dropping the article and preposition before the second noun, which is not standard when both nouns are definite and separate items.

So you should keep:

στο ύφος και στο λεξιλόγιο

What gender and plural forms do ύφος and λεξιλόγιο have?

Both nouns are neuter.

ύφος (style):

Singular:
- το ύφος (nominative/accusative) – the style
- του ύφους (genitive) – of the style
Plural (quite rare in actual use, but the form exists):
- τα ύφη (nominative/accusative) – styles
- των υφών (genitive)

λεξιλόγιο (vocabulary):

Singular:
- το λεξιλόγιο (nom./acc.) – the vocabulary
- του λεξιλογίου (gen.) – of the vocabulary
Plural:
- τα λεξιλόγια (nom./acc.) – vocabularies (used when talking about several vocabularies, e.g., of different authors)
- των λεξιλογίων (gen.)

In your sentence, both are neuter singular accusative governed by στο (= σε + το).

Could I say Η σύγκριση με τα παλιά μου κείμενα φαίνεται μεγάλη instead of δείχνει μεγάλη διαφορά? What’s the difference in meaning?

You could say:

Η σύγκριση με τα παλιά μου κείμενα φαίνεται μεγάλη.
= The comparison with my old texts seems big.

But this shifts the meaning:

δείχνει μεγάλη διαφορά – shows/reveals a big difference
- Focus: the result of the comparison is that a big difference becomes apparent.
φαίνεται μεγάλη – seems big/appears big
- Focus: how the comparison itself looks/appears to you.

To keep the original idea (“the comparison reveals a big difference in style and vocabulary”), δείχνει μεγάλη διαφορά is more precise.