Bilirkişi dosya üzerinden incelemeyi yapıyor.

Bilirkişi means expert, especially in a legal or official context: an expert witness, court-appointed expert, or specialist examiner.

It is written as one word in modern Turkish. Historically, it comes from something like bilen kişi (a person who knows), but as a set term it has become bilirkişi.

So in this sentence, bilirkişi is the subject: the person carrying out the examination.

Because it is the definite direct object of the verb yapmak.

• inceleme = examination / review
• incelemeyi = the examination / the review as a specific object

The ending -(y)i is the accusative case. Turkish uses the accusative when the direct object is specific or definite.

So:

• inceleme yapıyor = is doing an examination / doing examination work
• incelemeyi yapıyor = is doing the examination

The y is a buffer consonant added between two vowels:

• inceleme + i would be awkward
• so Turkish uses incelemeyi

Turkish often uses a noun + yapmak structure where English might prefer a simple verb.

Here:

• inceleme yapmak = to conduct an examination / to carry out a review

So incelemeyi yapıyor literally looks like is doing the examination, but in natural English it often corresponds to is conducting the review/examination.

This structure is very common in Turkish:

• araştırma yapmak = to do research
• kontrol yapmak = to do a check
• inceleme yapmak = to conduct an examination

Dosya üzerinden means something like:

• based on the file
• through the file
• on the basis of the case file/documents
• without an in-person inspection, just from the file

The key word is üzerinden, which often means:

• over
• via
• through
• on the basis of

In legal or bureaucratic Turkish, dosya üzerinden inceleme yapmak usually means the expert is reviewing the matter from the file/documents alone, rather than, for example, visiting a place or examining a person directly.

Because üzerinden expresses the method or basis of the action.

Compare:

• dosyayı inceliyor = he/she is examining the file
• dosyada = in the file
• dosya üzerinden inceleme yapıyor = he/she is conducting an examination based on the file

So here the point is not simply that the file is the object being looked at, but that the examination is being carried out by means of / on the basis of the file.

It comes from:

• üzeri = its top / its surface / over it
• -nden / -den = ablative ending, often meaning from

So üzerinden literally has a sense like from over it / over it / via it.

In modern usage, it often functions as a fixed postposition meaning:

• through
• via
• by way of
• based on

Examples:

• internet üzerinden = via the internet
• telefon üzerinden = over the phone
• dosya üzerinden = via the file / based on the file

Yapıyor is the present continuous form of yapmak (to do / to make).

Breakdown:

• yap- = do
• -ıyor = present continuous

So it means:

• is doing
• is carrying out

Depending on context, Turkish present continuous can also sometimes translate as a habitual present, but here the most natural reading is is carrying out or is conducting.

Turkish does not have articles like English a/an and the.

Instead, definiteness is often shown through:

• context
• word order
• the accusative case on direct objects

Here, incelemeyi is specific because of the accusative ending -(y)i, so English often translates it as the examination.

Similarly, bilirkişi can mean the expert or an expert depending on context. In this sentence, since it is clearly a known participant in the situation, English often uses the expert.

The sentence is:

Bilirkişi dosya üzerinden incelemeyi yapıyor.

The basic parts are:

• Bilirkişi = subject
• dosya üzerinden = adverbial phrase showing basis/method
• incelemeyi = direct object
• yapıyor = verb

So the structure is:

Subject + adverbial phrase + object + verb

This is very natural in Turkish, since Turkish normally puts the verb at the end.

A rough literal order would be: The expert, based on the file, the examination is doing.

More natural English: The expert is conducting the examination based on the file.

Yes. That version is also natural, but the nuance is slightly different.

• inceleme yapıyor = is conducting an examination / is doing review work
• incelemeyi yapıyor = is conducting the specific examination

So the version with incelemeyi sounds more definite and specific.

In real Turkish, both can occur depending on context.

Mostly, yes. It is especially common in:

• courts
• legal reports
• official investigations
• administrative procedures

In everyday speech, if you just want to say expert, people often use:

• uzman

But bilirkişi has a more specific institutional/legal flavor.

So in this sentence, the context strongly sounds legal or official.

Yes. The whole sentence sounds quite formal, bureaucratic, or legal.

That is because of words and phrases like:

• bilirkişi
• dosya üzerinden
• inceleme yapmak

In casual everyday speech, people might choose simpler wording. But in reports, court documents, or official explanations, this style is very common.

A very literal translation would be:

The expert is doing the examination over/through the file.

A more natural English version would be:

• The expert is conducting the examination based on the file.
• The expert is reviewing the case file and conducting the examination accordingly.
• The expert is carrying out the examination on the basis of the file.

The exact best translation depends on the legal context, but grammatically the Turkish sentence is built exactly around that idea.