Here it is in fact silent! This is very common in eastern Norwegian with the flap-r. It is not silent in front of all consonants, but I do not have the rule right now.However, if there is a possibility of retroflex fusion (r+t/d/s/n) then this will always happen, and so the r-sound will be lost, but the following consonant will be retroflex. "Har du" will never sound like "ha du". Native speaker here.
When r comes before d, t, s, n and l, it's pulled back (towards the throat) and becomes the retroflex approximant "ɻ". This change happens regardless whether it is touching the aforementioned letters or not. It also forces the change of the following letter into its retroflex equivalent (d into ɖ, t into ʈ, s into ʂ, n into ɳ, l into ɭ). Otherwise, it's pronounced as an alveolar flap "ɾ" (single rolled r).
However, there is no postalveolarisation or any kind of sandhi happening when "r" comes before "j" so it should not be silent nor retroflexed, only pronounced as the alveolar flap which indeed is less prominent than the alveolar trill given that the flap is single rolled. On the other hand, literature is not certain about r-drop really happening before non-dental consonants like "j" (has been observed in East Norwegian), but this phonetic change is not part of Standard East Norwegian so it shouldn't worry you.
Click here to notice the difference between the alveolar flap "ɾ" and the retroflex approximant "ɻ".
This course isn't meant to be a phrase book.
The aim of the course is to teach you the syntax needed to form your own sentences, and to provide you with a basic vocabulary to use as building blocks when doing so. :)
"Does [the subject] have [an object]?" is not a trivial sentence structure to have in one's arsenal.
In this case, yes. Norwegian does not use an auxiliary verb to form questions, but in English "do/does" is often used in that capacity.
To turn a Norwegian statement into a question, you just make the verb and the subject switch places: "Jeg har et barn." -> "Har jeg et barn?"
It's basically like old English. Imagine like someone off the films saying "Have I a child?"