"The window is glass."
Translation:Das Fenster ist aus Glas.
Is the word "aus" needed? Is it more proper? I put in "Das Fenster ist Glas." and got it right, but I was just wondering.
Same for me, but probably in your comment there is also the answer: "aus" is not required but now we are studying dative and so I suppose DL prefers the sentence with "aus". Comments from native German are welcome.