"Wil ik de schildpad?"
Translation:Do I want the turtle?
If you change round the subject and the verb it forms a question in Dutch: "ik wil de schildpad" = I want the turtle; "wil ik de schildpad" = Do I want the turtle?
Technically you can phrase it just like the declarative sentence too, as long as you include the question mark (or, in spoken language, an upward infection). I would avoid doing so on Duolingo though since the software may not be the best at picking up on that. Also, in English doing so implies that you are looking for confirmation or similar, which I don't think the Dutch sentence does.