"We even have soup with fish."
Translation:Vi har endda suppe med fisk.
Let me give you another example. Consider these Danish sentences:
"De har stjålet alt hendes legetøj. De har endda taget hendes bamser."
"De har stjålet alt hendes legetøj. Selv hendes bamser har de taget."
The first sentence makes you think that her teddy bears were her favorite toys, so the fact that "they even took her teddy bears" in this case is especially cruel. The emphasis is on how audacious this deed was.
In the second sentence, one gets the feeling that maybe the teddy bears were in a different place than the other toys, or toy thieves don't normally go for those. And you get the feeling that the speaker is trying to emphasise just how many toys are missing, rather than directly emphasising how sad it is for the child (although that is of course implied).
(By the way, she got all the toys back the very next day and also got a free lollipop at the post office. Don't worry!)
"Selv" also means "even" in the same way. However, it is always used with a different word order, because otherwise it would be mistaken for the more common usage of "selv" (meaning "myself"/"ourselves"). So in this sentence, you could say: "Selv suppe med fisk har vi." (which would be correct but not elegant). The subtle difference between these uses of "endda" and "selv": "endda" implies something being impressive (fishing for a "wow!" reaction). On top of all the great (or, in another context, terrible) things you've already heard, there's endda this thing. "Selv" is more about completeness. When using "selv", you are implying that if you have soup with fish, you must have everything. Surely nobody expected that you would have soup with fish. Maybe it's really unusual to put fish in soup, but because you're just that big on fish, you do selv that.