Η αδιαφορία του με ξάφνιασε, γιατί εγώ ένιωθα μόνο θαυμασμό για την προσπάθειά της.

Greek uses the definite article much more often than English.

So η αδιαφορία του is the normal Greek way to say his indifference:

• η αδιαφορία = the indifference
• του = his / of him

A very literal breakdown would be the indifference of him, but in natural English that becomes his indifference.

Here του and της are weak possessive pronouns in the genitive.

• η αδιαφορία του = his indifference
• την προσπάθειά της = her effort

This is a very common Greek pattern: the possessed noun comes first, and the possessor comes after it.

Also, the same forms του and της can mean to him and to her in other sentences, so context matters. In this sentence, after nouns, they are possessive: his and her.

Με is the weak form of me and it is the direct object of the verb ξάφνιασε.

In standard Greek, weak object pronouns usually come before a finite verb:

• με ξάφνιασε = surprised me
• με είδε = saw me
• με ξέρει = knows me

So Greek says me surprised, not surprised me, in terms of word order.

Ξάφνιασε is the aorist form of ξαφνιάζω.

Here it shows a single, complete event in the past:

• με ξάφνιασε = it surprised me

The idea is that his indifference struck the speaker as one whole event or reaction, not as an ongoing repeated process.

Ένιωθα is the imperfect of νιώθω / νιώθω and it suggests an ongoing state or feeling in the past.

So the contrast is:

• με ξάφνιασε = one completed event
• ένιωθα = what I was feeling at the time, as an ongoing inner state

This is a very common Greek tense contrast:

• aorist for the main event
• imperfect for background, duration, or repeated feeling/action

If the sentence had ένιωσα, it would sound more like I felt admiration at that moment rather than I was feeling admiration.

Yes, the verb already shows the subject, so εγώ is not required grammatically.

It is included for emphasis or contrast.

Without εγώ:

• γιατί ένιωθα μόνο θαυμασμό...

With εγώ:

• γιατί εγώ ένιωθα μόνο θαυμασμό...

The version with εγώ sounds more like:

• because I, for my part, felt only admiration
• because as for me, I felt only admiration

So it adds a contrast between his indifference and my reaction.

Greek often leaves out the article with abstract nouns when speaking in a general, non-specific way.

So:

• ένιωθα μόνο θαυμασμό = I felt only admiration

This sounds natural because admiration here is being treated as a feeling in general, not as a specific, already identified thing.

If you added the article, τον θαυμασμό, it would sound more specific or marked, and in this sentence the article-free version is the natural one.

Because Greek commonly uses the pattern:

• θαυμασμός για κάτι/κάποιον = admiration for something/someone

So:

• θαυμασμό για την προσπάθειά της = admiration for her effort

This is just the normal combination of noun + preposition here.

A more verb-based way to express a similar idea would be:

• θαύμαζα την προσπάθειά της = I admired her effort

But the sentence you have uses the noun θαυμασμό instead.

This is a spelling rule connected with enclitics, and της here is an enclitic.

When words like μου, σου, του, της follow certain nouns, Greek may add an extra written accent to show the stress clearly:

• η προσπάθειά της
• το όνομά μου

So the base noun is still προσπάθεια. The extra accent does not change the meaning; it is an orthographic stress rule.

Here is the basic case structure:

• η αδιαφορία — nominative, because it is the subject
• του — genitive, showing possession: his
• με — accusative, direct object: me
• θαυμασμό — accusative, object of ένιωθα
• την προσπάθειά της — accusative after για
• της — genitive, showing possession: her

So this sentence is a nice example of how Greek uses:

• nominative for the subject
• accusative for objects and after many prepositions
• genitive for possession

No, Greek word order is fairly flexible, although some versions sound more neutral than others.

Your sentence is natural, but other orders are possible, for example:

• Με ξάφνιασε η αδιαφορία του...
• Η αδιαφορία του με ξάφνιασε...

Both are correct. The difference is mostly about focus and style.

• Η αδιαφορία του... puts emphasis first on his indifference
• Με ξάφνιασε... starts with the effect on me

The original sentence feels balanced and very natural.

Because γιατί introduces an explanatory clause: the second part gives the reason for the first part.

So the structure is:

• Η αδιαφορία του με ξάφνιασε,
• γιατί εγώ ένιωθα μόνο θαυμασμό...

In Greek, this comma is normal and helps separate the main statement from the reason that follows.

Yes, in many contexts γιατί and επειδή can both mean because.

But γιατί is extremely common in everyday Greek and sounds very natural here.

Very roughly:

• γιατί = common, conversational, flexible
• επειδή = also standard, sometimes slightly more formal or explicitly causal

So this sentence could also be written with επειδή, but γιατί is a very natural choice.