This is the 10212th most frequent Turkish word.
beklemediklerini
"Things they did not expect."
Here, 'beklemediklerini' reflects the object (that they weren't expecting something) in the statement.
Onların beklemediklerini anladım.
I understood that they didn't expect it.
In this case, 'beklemediklerini' refers to the subject matter that needs to be explained.
Beklemediklerini anlatmam gerekiyor.
I need to explain what they didn't expect.
Here, 'beklemediklerini' is the complement to 'söylediler,' explaining what 'they' said they didn't expect.