Ο αρραβωνιαστικός της θέλει μια απλή βέρα, όχι κάτι πολύ ακριβό.

Ο is the masculine singular definite article, meaning the.

So:

• ο αρραβωνιαστικός = the fiancé

Greek uses definite articles very often, including in places where English might or might not use the. Here it is simply the normal way to say the fiancé.

αρραβωνιαστικός is in the nominative singular masculine because it is the subject of the sentence: he is the one doing the wanting.

The ending -ός is a very common masculine ending in Greek. In dictionary form, many masculine nouns and adjectives appear like this.

Here the full phrase is:

• ο αρραβωνιαστικός = the fiancé

If the word changed case, its form could change too. For example, in other contexts you might see related forms like του αρραβωνιαστικού.

In Greek, possession is often shown with a weak genitive pronoun placed after the noun.

So:

• ο αρραβωνιαστικός της = literally the fiancé of her
• natural English: her fiancé

This is a very common pattern:

• το βιβλίο μου = my book
• η φίλη σου = your friend
• ο αδερφός της = her brother

So even though English puts the possessive before the noun, Greek often puts this short possessive form after it.

Yes. της can serve more than one role, depending on context.

Here it is a genitive possessive pronoun:

• ο αρραβωνιαστικός της = her fiancé

But της can also mean to her in other sentences:

• Της μιλάω. = I’m speaking to her.

Greek often uses the same form for:

• possession: her
• indirect object: to her

The function is understood from the sentence structure.

θέλει is the 3rd person singular present tense of θέλω = to want.

So:

• θέλω = I want
• θέλεις = you want
• θέλει = he/she/it wants

In this sentence, the subject is ο αρραβωνιαστικός της, which is singular, so the verb must also be singular:

• Ο αρραβωνιαστικός της θέλει... = Her fiancé wants...

Greek verbs usually show the subject through their endings, so the ending -ει tells you this is he/she/it wants.

Greek usually does not need an explicit subject pronoun when the subject is already clear.

Here the subject is already stated:

• Ο αρραβωνιαστικός της = her fiancé

So Greek does not need to add he. In fact, adding a pronoun would often sound unnecessary unless you wanted emphasis or contrast.

Greek is a pro-drop language, meaning subject pronouns are often omitted because the verb ending already helps identify the person.

μια is the feminine singular form of a/an because βέρα is a feminine noun.

Greek indefinite articles agree with the gender of the noun:

• ένας for masculine
• μια / μία for feminine
• ένα for neuter

So:

• μια βέρα = a ring
  because βέρα is feminine.

They are the same word. The difference is mostly spelling style and emphasis.

• μια is very common in everyday writing.
• μία may be used in more careful writing or when you want to stress one.

In normal modern Greek, both are acceptable in many contexts. Here μια απλή βέρα is completely natural.

απλή is an adjective meaning simple/plain and it agrees with βέρα.

Since βέρα is:

• feminine
• singular
• accusative here (because it is the object of θέλει)

the adjective also appears in the matching feminine singular form:

• μια απλή βέρα

Greek adjectives must agree with the nouns they describe in gender, number, and case.

Greek adjectives can sometimes come after the noun, but the most neutral and common position here is before the noun:

• μια απλή βέρα

Putting it after the noun can sound marked, stylistic, or more limited by context. For a basic descriptive phrase, learners should treat adjective + noun as the normal choice here.

So μια απλή βέρα is the natural default.

Not quite. βέρα is specifically a wedding band or plain marriage ring, not just any ring in general.

A more general word for ring is:

• δαχτυλίδι

So:

• βέρα = wedding band / marriage ring
• δαχτυλίδι = ring in general

That is why απλή βέρα sounds especially natural: wedding bands are often thought of as plain, simple rings.

This part means not something very expensive.

It is a very natural Greek way to soften or generalize the idea. Instead of repeating βέρα, Greek uses κάτι = something:

• όχι = not
• κάτι = something
• πολύ ακριβό = very expensive

So the phrase means:

• not something very expensive

This is similar to English, where you might say:

• He wants a simple wedding band, not something very expensive.

Because it goes with κάτι, and κάτι behaves as neuter.

So:

• κάτι ακριβό = something expensive
• κάτι καλό = something good
• κάτι περίεργο = something strange

Even though the actual object being talked about is βέρα, the adjective here is agreeing with κάτι, not with βέρα.

That is why Greek uses the neuter form:

• ακριβό, not ακριβή

The comma marks a contrast:

• μια απλή βέρα
• όχι κάτι πολύ ακριβό

It works like English:

• a simple ring, not something very expensive

The second part corrects or narrows the first idea. The comma helps show that contrast clearly.

πολύ means very in this sentence. It intensifies the adjective ακριβό:

• ακριβό = expensive
• πολύ ακριβό = very expensive

This is a common pattern:

• πολύ καλό = very good
• πολύ μεγάλο = very big
• πολύ ωραίο = very nice

So κάτι πολύ ακριβό means something very expensive.

It is possible in some contexts to leave out the indefinite article, but here μια απλή βέρα is the most natural and complete phrasing.

Including μια makes it sound like:

• he wants a simple wedding band

Without it, the phrase can sound more general, more compressed, or more dependent on context. For learners, it is safest to use μια here.

Greek word order is more flexible than English, but the original order is very natural and neutral:

• Ο αρραβωνιαστικός της θέλει μια απλή βέρα, όχι κάτι πολύ ακριβό.

Other orders are possible for emphasis, but they would change the focus or sound less neutral. For example, moving όχι κάτι πολύ ακριβό earlier would emphasize the contrast more strongly.

So for normal use, the given word order is the one learners should remember.