Απάντησα ειλικρινά στον πραγματογνώμονα.

Απάντησα is the past simple form of the verb απαντώ (to answer).
The ending -σα is very common in Greek for the aorist past, which usually presents the action as a single completed event.

So:

• απαντώ = I answer / I am answering
• απάντησα = I answered

In this sentence, Απάντησα means I answered as one completed action.

Greek usually does not need subject pronouns when the verb already shows who the subject is.

Here, Απάντησα clearly means I answered, so adding εγώ is normally unnecessary.

You could say Εγώ απάντησα if you wanted emphasis, such as:

• I answered, not someone else.

But in a neutral sentence, Greek typically leaves the pronoun out.

Ειλικρινά is an adverb, and here it means honestly or in an honest way.

It describes how the person answered.

So:

• Απάντησα = I answered
• ειλικρινά = honestly

Together: I answered honestly.

Yes. Ειλικρινής is the adjective meaning honest / sincere, and ειλικρινά is the adverb meaning honestly / sincerely.

Compare:

• ειλικρινής άνθρωπος = an honest person
• μιλάει ειλικρινά = he/she speaks honestly

So in your sentence, Greek uses the adverb form because it modifies the verb answered.

Στον is a contraction of σε + τον.

• σε = to / at / in
• τον = the (masculine singular, accusative)

So:

• σε τον πραγματογνώμονα becomes
• στον πραγματογνώμονα

With the verb απαντώ, Greek commonly says απαντώ σε κάποιον = answer someone / answer to someone.

Because after στον the noun must be in the accusative singular.

The dictionary form is:

• ο πραγματογνώμονας = the expert witness / expert

But after στον, it changes:

• στον πραγματογνώμονα

So this is a case change:

• Nominative: ο πραγματογνώμονας
• Accusative: τον πραγματογνώμονα

This is very common in Greek masculine nouns.

Πραγματογνώμονας is a fairly formal word. It usually means expert witness, court-appointed expert, or more generally expert examiner / specialist giving an official opinion, depending on context.

So στον πραγματογνώμονα means to the expert or to the expert witness.

The exact English translation depends on the situation, especially whether it is legal, forensic, technical, or administrative.

Greek uses the definite article much more often than English.

Here, στον πραγματογνώμονα means to the expert witness / to the expert, referring to a specific person already known in the context.

Leaving the article out would usually sound less natural in a sentence like this, unless you were using a different structure or speaking in a very special context.

So the article is normal and expected here.

Yes. Greek word order is fairly flexible, because the verb ending and case forms already show the grammatical relationships.

The neutral order here is:

• Απάντησα ειλικρινά στον πραγματογνώμονα.

But other orders are possible, for example:

• Στον πραγματογνώμονα απάντησα ειλικρινά.
• Ειλικρινά απάντησα στον πραγματογνώμονα.

These can slightly change the emphasis, but the basic meaning stays the same.

With απαντώ, Greek normally uses σε for the person receiving the answer:

• απαντώ σε κάποιον = answer someone

So Greek treats that person more like an indirect object, even though English may use a direct object.

That is why the sentence has:

• στον πραγματογνώμονα = to the expert witness

This is a very important pattern to remember with απαντώ.

These forms express different aspects or time frames:

• Απάντησα = I answered
  A single completed action.

• Απαντούσα = I was answering / I used to answer
  Ongoing, repeated, or background past action.

• Έχω απαντήσει = I have answered
  A completed action with present relevance.

So Απάντησα ειλικρινά στον πραγματογνώμονα presents the answer as one complete past event.

The grammar is completely normal, but the noun πραγματογνώμονας is relatively formal and specialized. It is not a word you hear in casual everyday conversation unless the topic is legal, technical, insurance-related, or forensic.

The rest of the sentence is straightforward and natural Greek.