Tanık neden tekrar sorgulandığını bilmiyordu.

Turkish often uses a bare noun where English would use a/an or the.

Here, tanık is the subject of the sentence, so it appears in the basic nominative form, with no case ending:

• tanık = witness

Whether it means a witness or the witness depends on context. In a real situation, this sentence would often be understood as the witness because the person is already known in the conversation.

So:

• tanık = witness / the witness / a witness, depending on context
• no extra ending is needed because it is the subject

Because neden tekrar sorgulandığını is an embedded question inside a larger sentence.

The sentence structure is roughly:

• Tanık = the witness
• neden tekrar sorgulandığını = why he/she was being questioned again
• bilmiyordu = did not know

So the witness did not know why...

In Turkish, embedded clauses usually come before the main verb, and the main verb often stays at the end. That is why neden is at the beginning of the embedded clause, not necessarily at the beginning of the entire sentence.

Tekrar means again.

In this sentence, it belongs with sorgulandığını, so the idea is:

• neden tekrar sorgulandığını = why he/she was being questioned again

So tekrar modifies the questioning, not the knowing.

In other words, the sentence means the witness did not know the reason for the repeated questioning, not that the witness again did not know.

Yes. It comes from the verb sorgulamak, which means to question / interrogate.

From that:

• sorgulamak = to question someone
• sorgulanmak = to be questioned / to be interrogated

So sorgulandığını contains the passive idea was being questioned or was questioned, depending on context.

Turkish often leaves the agent unstated in passive sentences, just like English can:

• He was questioned without saying by whom.

A helpful breakdown is:

• sorgula- = question / interrogate
• -n- = passive
• -dık = a nominalizing/subordinate-clause ending
• -ı = 3rd person singular agreement/possessive marker
• -nı = accusative ending on the whole clause

So the form is essentially:

• sorgulan-dık-ı-nı

But because of normal sound changes, it appears as:

• sorgulandığını

A natural English-style gloss would be something like:

• that he/she was questioned or in this sentence more specifically:
• why he/she was being questioned

Because Turkish often omits subjects when they are clear from context.

In this sentence, the embedded clause does not name the person being questioned separately. The listener usually understands it from context. Very often, the natural interpretation is that it refers back to tanık:

• The witness did not know why the witness was being questioned again.

Also, Turkish does not force you to choose he or she in the way English does. A 3rd-person form can stay neutral unless context makes it clear.

If you wanted to state the embedded subject explicitly, Turkish would normally mark it in the genitive:

• Tanık, sanığın neden tekrar sorgulandığını bilmiyordu.
• The witness did not know why the suspect was being questioned again.

Here sanığın explicitly tells you who was being questioned.

Because the whole embedded clause functions as the object of bilmek (to know).

Turkish commonly uses an accusative-marked nominalized clause after verbs like:

• bilmek = to know
• görmek = to see
• duymak = to hear

So in:

• neden tekrar sorgulandığını bilmiyordu

the part sorgulandığını is inside a clause that is being treated like a noun phrase: the fact/reason that he/she was being questioned.

The final -nı is the accusative marker attached after the 3rd-person ending. The n is a buffer consonant.

You can compare:

• geldiğini biliyorum = I know that he/she came
• yaptığını gördüm = I saw that he/she did it

Bilmiyordu breaks down as:

• bil- = know
• -mi- = negative
• -yor- = imperfective/progressive
• -du = past

So literally it looks like was not knowing, but in natural English it is usually just:

• did not know

With stative verbs like bilmek (to know), Turkish often uses -iyor-du to describe a continuing state in the past. So bilmiyordu means that at that time, the state was: he/she didn’t know.

It is very normal Turkish.

It can often be translated either way depending on context.

Turkish forms like sorgulandığını do not always map neatly onto one exact English tense. In context, it can mean:

• why he was questioned
• why he was being questioned

Because the sentence includes tekrar and the situation sounds ongoing, English speakers will often prefer:

• The witness didn’t know why he was being questioned again.

But the Turkish form itself is not limited to just one English tense label.

Yes, but the given order is the most neutral and standard.

The default structure is:

• Subject + embedded clause + main verb
• Tanık + neden tekrar sorgulandığını + bilmiyordu

This fits Turkish’s usual tendency to put the main finite verb at the end.

You can move things around for emphasis, but then the sentence may sound more marked or stylistic. For example:

• Neden tekrar sorgulandığını tanık bilmiyordu.

This is possible, but it gives extra emphasis to neden tekrar sorgulandığını.

So for learners, the original order is the best one to treat as the normal pattern.