Spanish is spoken a lot faster than english. Im swedish, and swedish is spoken even slower than English... Spanish for me is like driving a F1-car in the hallway. I have no idea how I ever will be able to understand spoken Spanish :) Also I find Spanish a bit sludderish with the vocals... Very unclear.... Well, some day.... :)
This is just the user forum, so we can be of limited assistance.
When Duo marks your sentence as incorrect, it shows you a correct answer.
You should compare your answer and figure out why it is wrong, and use this forum to get any help you need.
Duo only displays one possible correct answer but accepts many more. If you show us what answer you have given, we can help check if it is correct.
You could copy the Duo correct answer to submit it when the same question comes around again - this would help you move on, but won't necessarily help with your learning.
You really need to understand why your answer is incorrect and learn to provide a correct answer.