When I started talking Danish around Charlotte, Marcel and Phyllis, I quickly realised they couldn’t tell /l/ and /ð/ apart (for instance, they confuse bål “bonfire” and båd “boat”).
My phonetic training meant that this didn’t shock me. The Danish /ð/ is an approximant, and is very close to an /l/, except that the tip of the tongue is touching the lower teeth.
However, today I was reading through some of the old postings on Rasmus Pinnerup’s blog, and he states that /ð/ is now often velarised, that is, [ð??] (shouldn’t there also be a diacritic to show it’s touching the lower teeth and not the top ones, btw?), and that makes it very similar to the English dark /l/ in ball.
I tested this theory by asking Phyllis which /l/ she finds the Danish /ð/ similar to, the English one or the German/French one, and she confirmed it was the former. So well spotted, Rasmus!
While we are on the topic of /ð/, it’s interesting that Léon still hasn’t figured out that he should make his tongue touch the lower teeth. Instead, he makes it touch the top left teeth. It looks weird, but it sounds right.