Questions & Answers about Wir sprechen darüber, dass er eine Phobie hat.
Why do we need darüber here? Can't I just say Wir sprechen, dass...?
No, you can't leave it out. The verb here is sprechen über (to talk about). When the thing you are talking about is an entire dass-clause rather than a simple noun, German uses a da-compound as a placeholder in the main clause. darüber literally means 'about it,' acting as a bridge to the dass-clause. It translates smoothly to 'about the fact' in English.
Why does darüber have an 'r' in the middle instead of just being daüber?
It is just for pronunciation! When you form a da-compound with a preposition that starts with a vowel (like über), you insert an -r- to break up the two vowels. So, da + über becomes darüber. If the preposition started with a consonant, like mit, it would just be damit.
Could I use davon instead of darüber in this sentence?
Yes, you could say Wir sprechen davon, dass... because both sprechen über and sprechen von mean 'to talk about.' However, sprechen über (and therefore darüber) usually implies having a deeper discussion or conversation about a topic, while sprechen von can just mean casually mentioning it.
Just as a refresher, why is hat at the very end of the sentence?