Breakdown of Nous avons vraiment besoin de ce dont tu parles.
tu
you (informal singular)
nous
we / us (object pronoun)
parler
to speak
vraiment
really
Questions & Answers about Nous avons vraiment besoin de ce dont tu parles.
Why is it ce dont here instead of ce que?
We use ce dont (meaning "what" or "the thing that") when the verb in the relative clause requires the preposition de. Here, the verb is parler de (to talk about). If the verb didn't take de, we would use ce que (like in ce que tu dis - what you are saying).
If dont already replaces a phrase with de, why is there another de right before ce dont?
That first de belongs to the expression avoir besoin de (to need). The second part of the sentence uses parler de (to talk about). So literally, the sentence says: "We have really need of (de) the thing about which (ce dont) you speak." Because both verbs require de, both parts of the sentence show it!
Why is vraiment placed between avons and besoin?
Could I just say "Nous avons vraiment besoin dont tu parles" without the ce?