Osiguratelj nikako ne odgovara.

Osiguratelj means insurer.

In this sentence it is:

• a masculine singular noun
• in the nominative case
• the subject of the sentence

So osiguratelj is the one doing or being something here: the insurer is the one that does not respond / is not liable, depending on context.

Odgovara is the 3rd person singular present tense of odgovarati.

The verb odgovarati can mean different things depending on context, especially:

• to answer / reply
• to be responsible / liable
• to suit / fit

In this sentence, the intended meaning is the one already given in your learning context, not necessarily the most basic dictionary meaning. So even though odgovara often means answers, here it can mean something like is liable / is responsible, if that is the sense intended by the full context.

In Croatian, ne is the basic negation used with verbs, while nikako strengthens the meaning.

So:

• ne odgovara = does not answer / is not liable
• nikako ne odgovara = absolutely does not answer / is in no way liable / definitely not

This is normal Croatian usage. English often avoids double negatives in standard grammar, but Croatian commonly uses multiple negative elements together for emphasis.

Here nikako means something like:

• in no way
• by no means
• absolutely not
• not at all

It adds strong emphasis.

A useful thing to know is that nikako can sometimes have slightly different shades depending on context, but in a sentence like this it strongly reinforces the negation.

Because this sentence uses the verb odgovarati, not the adjective odgovoran.

Compare:

• Osiguratelj ne odgovara.
  = The insurer does not answer / is not liable.

• Osiguratelj nije odgovoran.
  = The insurer is not responsible.

So:

• odgovara = a verb form
• odgovoran = an adjective

Both can sometimes lead to similar English translations, but the Croatian grammar is different.

Yes. Odgovara is present tense, 3rd person singular.

It matches the singular subject osiguratelj.

The full pattern is:

• ja odgovaram = I answer
• ti odgovaraš = you answer
• on/ona/ono odgovara = he/she/it answers

So osiguratelj odgovara literally means the insurer answers / is liable, and with negation:

• osiguratelj ne odgovara
• osiguratelj nikako ne odgovara

Croatian often leaves out information that is understood from context.

For example, you could have fuller sentences like:

• Osiguratelj ne odgovara za štetu. = The insurer is not liable for the damage.
• Osiguratelj ne odgovara na upit. = The insurer does not answer the inquiry.

In your sentence, the rest is omitted, so the sentence sounds more general:

• Osiguratelj nikako ne odgovara.

The exact nuance depends on the context you were given.

Yes, Croatian word order is fairly flexible, but the given order is natural and neutral.

Osiguratelj nikako ne odgovara. is a normal way to say it.

Other orders are possible, but they may sound more marked or emphatic, for example:

• Nikako osiguratelj ne odgovara.
• Osiguratelj ne odgovara nikako.

These are not always equally natural in every context. For a learner, the original order is the safest choice.

A common difficulty for English speakers is the ending -lj.

Very roughly:

• osiguratelj ≈ o-see-goo-RA-tely

The lj sound is like a soft ly sound, similar to the lli in some pronunciations of million, though not exactly the same in all accents.

Also:

• o-si-gu-ra-telj
• stress is usually heard on ra in careful pronunciation

You do not pronounce the final j as a separate English j sound.

Grammatically, osiguratelj is a singular masculine noun, but in actual usage it can refer to:

• an insurer as a legal entity or company
• sometimes an insurance provider more generally

So even though the noun is grammatically masculine singular, it does not necessarily mean a single male person. In legal and business language, Croatian often uses such nouns for institutions or entities.

Yes, it sounds fairly formal and could easily appear in:

• legal language
• insurance terms
• official statements
• business communication

Especially with words like osiguratelj and a phrase like nikako ne odgovara, the tone is more formal than everyday casual speech.