Im confused about die der and den
It's called noun declension. There's a lot of good information on it on about.com
Why can it not be "Die Ente ist spielen"? Instead it is "Die Ente spielt".
What mekes something feminine?
grammatical gender is arbitrary. There are a few general rules, however. Just google it.
General rules: http://www.learn-german-smarter.com/learn-german-articles.html
couldnt it be die ente apgespielt???