The primary time we use “dont”

So far, you’ve learned that que can be translated to that. E.g. The house that I bought.

And you’ve also learned that que is only applicable when the verb uses a direct object, which is fine with this phrase: La maison que j’ai achetée. because acheter is a verbe transitif direct.

When a verb (or expression) needs a preposition, the object is indirect (and the verb therefore transitif indirect), so we need a different pronom relatif.

The pronom relatif that we use depends on the preposition required.

Today, the preposition is de and the something else is dont.