Only when it is followed by the hard vowels: e,i,y,ä or ö. In this case skö. :)
I just noticed that you have a typo, you wrote 'hard vowels' but you mean soft vowels.
Hard vowels are a o u å – SK sounds like SK before those
Soft vowels are e i y ä ö – SK sounds like [ɧ] before them
So the literal translation is "shield" "toad". Which is think is almost as awesome as fladdermus being "flutter" "mouse" for bat.
How to pronoune that? It is a very difficult word. All I hear is "fnpadan".
How is the "Sk" meant to be pronounced it sounds like and English "f" from fish when the computer says it?
Wait, apparently sköldpaddan means both 'the turtle' and 'the tortoise'. So which is it? Because they're not the same thing.
It means both. If you want to distinguish between them, en landsköldpadda is a tortoise, and en vattensköldpadda is a turtle.
However, Wikipedia says this: The meaning of the word turtle differs from region to region. In North America, all chelonians are commonly called turtles, including terrapins and tortoises. In Great Britain, the word turtle is used for sea-dwelling species, but not for tortoises.