Dosya incelendi; üstelik bilirkişi rapor hazırladı.

The file was examined; moreover, the expert prepared a report.

Breakdown of Dosya incelendi; üstelik bilirkişi rapor hazırladı.

• hazırlamak: to prepare
• incelemek: to examine
• rapor: the report
• dosya: the file

Questions & Answers about Dosya incelendi; üstelik bilirkişi rapor hazırladı.

Why does dosya mean the file here even though there is no word like the in Turkish?

Turkish has no articles like the or a/an. Whether dosya is understood as the file, a file, or just file depends on context.

In a sentence like Dosya incelendi, English usually translates it as The file was examined because it sounds like a specific file already known in the situation.

Why is it dosya and not dosyayı?

Because this sentence uses the passive.

• Aktive: Birisi dosyayı inceledi. = Someone examined the file.
• Passive: Dosya incelendi. = The file was examined.

In the active sentence, dosyayı is the direct object, so it takes the accusative ending -yı.
In the passive sentence, dosya becomes the grammatical subject, so it appears without that accusative ending.

What exactly is incelendi grammatically?

İncelendi is the verb incelemek (to examine / inspect / review) in the passive past form.

You can break it down roughly like this:

• incele- = verb stem
• -n- = passive marker
• -di = past tense

So incelendi means was examined.