Learn Hardcore Turkish: Raporda bahsedilen eksik veriler tekrar tespit edildi. - The missing data mentioned in the report were detected again.

rapor+da: “in the report” (locative case)
bahsedilen: the passive past participle of bahsetmek (“to mention”), functioning like “mentioned”

Together, it literally means “mentioned in the report.”

Why is rapor in the locative case (-da) and not in the ablative (-den)?

The locative -da marks the place where something happens: the mentioning takes place in the report.
If you used the ablative rapordan, it would mean “from the report,” which would imply data were taken out of the report, not that the report is where they were spoken about.

What kind of participle is -ilen in bahsedilen, and why is it before the noun?

The suffix -ilen is a past passive participle suffix. It turns the verb bahsetmek into an adjective meaning “that was mentioned.” In Turkish, participial adjectives always precede the noun they modify, just like relative clauses in English (“the book that was read” → okunan kitap).

How is the passive voice formed in tespit edildi, and what does it mean?

Active base: tespit etmek (“to determine”)
Passive: replace et- with edil- → tespit edilmek (“to be determined”)
Past tense: add -di → tespit edildi (“was determined”)

So tespit edildi means “was determined.”

Why is there no explicit subject in this sentence?

Turkish often omits the agent when using the passive voice or when the doer is either unknown or unimportant. Here, the focus is on the action (“were determined again”) rather than on who performed it.

What is the role of tekrar in tekrar tespit edildi? Could I use yeniden instead?

tekrar and yeniden both mean “again” or “once more.”
They are interchangeable here: tekrar tespit edildi = yeniden tespit edildi.
Placement: as an adverb, it typically comes just before the verb phrase.

Why is it eksik veriler and not eksiklik veriler or veri eksikliği?

eksik veriler literally means “missing data,” using eksik (“missing/deficient”) as an adjective.
eksiklik is a noun meaning “lack” or “shortage,” so eksiklik veriler would be ungrammatical (“lack data”).
veri eksikliği (“data deficiency”) is a grammatical alternative, but it shifts the focus: it labels the situation as a “deficiency” rather than describing the data themselves as missing.

Can the word order change? For example, could I say Eksik veriler raporda bahsedilen tekrar tespit edildi?

While Turkish is relatively flexible, this particular rearrangement is awkward because:

raporda bahsedilen must directly modify eksik veriler.
Adverb tekrar should appear close to the verb.

The original order keeps the modifier next to its noun and the adverb next to the verb, which is the most natural in Turkish.