So you don't use the article with an occupation in normal sentence but in question it is necessary?
There is no article with an occupation word when using the verb "vara" (vara, är, var, varit), for example "I am a journalist" = "Jag är journalist".
Unless it's a question, and you really don't know what it is, 'en domare', the concept in itself. I suppose that kind of questions mainly are put by children or language students. :-)
In English we have "What DOES a judge DO?" and we use that verb form twice but in Swedish it is just gör once and seems to be like "What does a judge?". Is this common in other constructions?
I wrote what is the judge doing and got it wrong. How would that be said in Swedish.