This is the 5386th most frequent Turkish word.
konuşulan
"Konuşulan" means "spoken" or "being talked about" in English.
Here, 'konuşulan' functions as a past participle and modifies the noun 'konular' (topics), indicating that these are topics that have been or are being discussed.
Konuşulan konular oldukça ilginçti.
The topics being discussed were quite interesting.
In this sentence, 'konuşulan' describes 'dilleri' (languages) as those that are spoken or being discussed.
Bu kitap, konuşulan dilleri öğrenmek isteyenler için yazılmıştır.
This book is written for those who want to learn spoken languages.
Here, 'konuşulanlar' refers to 'things that were discussed,' using 'konuşulan' in a nominalized form indicating the content of a discussion.