Learn Turkish: Gazeteci röportajda sırdan bahsetmemiş. - The journalist apparently didn't mention the secret in the interview.

It is built by adding the negative suffix -me followed by the reported past tense suffix -miş to the verb root bahset-. The -miş suffix tells us that the speaker did not hear or read the interview themselves, but rather heard about it from someone else, or inferred it later.

Why is the word for secret, sır, written with the -dan ending here?

The verb bahsetmek (to mention / to talk about) always requires the ablative case (-dAn) for the topic being discussed. Even though we translate it as a direct object in English, in Turkish you talk "from" a topic. So "to mention the secret" becomes sırdan bahsetmek.

I know the helper verb for "to do" is etmek. What is the first part of bahsetmemiş?

It comes from the noun bahis (subject or topic). When combined with the helper verb etmek, the i in bahis drops out to make pronunciation smoother, creating the single compound verb bahsetmek.

What does the -ci suffix do in gazeteci?