Translation:Which animal has both tail and wings?
"Stjärt" is for fish and birds.
Mammals, like babbons, can have both "svans" (tail) and "stjärt" (buttocks).
The tail of an airplane is usually called "stjärtparti", but sometimes just "stjärt". In compound words you will probably see just "stjärt", for example T-tail is called "T-stjärt".
But, tailwind is called "medvind", so you can't translate everything word by word.
The nose of an airplane is called nos.
I know it's not really "wings" but first thing I thought of was:
It is the "a" that is pronounced incorrectly. I don't know how to explain it, but do you know how to pronounce the word "svenska"? It should be that kind of a instead of the one we hear here. Go to this website: https://en.wikipedia.org/wiki/Swedish_phonology The pronunciation for "svans" on Duolingo is used with the vowel sound of ɑː instead of a. I hope you understand, haha.