Questions & Answers about Ik vind het fijn dat jij auditie doet.
Why do we need het here if the sentence already has a dat-clause?
het acts as a placeholder object (an anticipatory object) for the verb vind. The real object of your opinion is the entire phrase dat jij auditie doet. Dutch uses het here to "announce" that the real object is coming later as a full clause. You are literally saying: "I find it nice, that you do an audition."
Is there a specific single verb for "to audition" in Dutch?
No, Dutch doesn't use a single verb for this. You must use the combination auditie doen (literally: to do audition).
Why is doet at the very end of the sentence?
The word dat introduces a subordinate clause. In Dutch subordinate clauses, the conjugated verb gets pushed to the end. Since the expression is auditie doen, the conjugated verb doet lands right after auditie.
The English translation says "I think", so why does the Dutch sentence use vind?
When you express a personal opinion, taste, or feeling about something (like finding it nice, beautiful, or boring), Dutch uses vinden. You only use denken for cognitive thoughts or expectations, like "I think it is going to rain."