Learn Dutch: We zitten na te denken over datgene wat de trofee uniek maakt. - We are sitting and thinking about that which makes the trophy unique.

Datgene wat is used to refer to an abstract thing or concept, translating to 'that which' or 'the thing that'. If we were talking about a specific person ('the one who'), we would use degene die. Because we are talking about the abstract concept of what makes the trophy unique, datgene wat is correct.

What does zitten add to the sentence? Why not just say We denken na?

Using zitten te plus an infinitive (here, na te denken) is the Dutch way of showing that an action is ongoing, similar to the English continuous '-ing' form. It literally means 'sitting to think', emphasizing that we are currently in the middle of pondering this.

Why is te placed in the middle of nadenken to form na te denken?

Nadenken (to think about / to reflect) is a separable verb made of the prefix na and the core verb denken. When a separable verb is used with te (which is required here by the zitten te construction), the word te must be sandwiched right between the prefix and the verb.

Why is maakt at the very end of the sentence?