abstract interface does not compile | Java

sry for the title, but why does the title not compile

1.    public abstract interface Herbivore {
2.            int amount = 10 ;
3.            public void eatGrass();
4.            public abstract int chew() { return 13; } 
5.   }
6.            
7.   abstract class IsAPlant extends Herbivore {
8.            Object eatGrass (int season) { return null;}
9.   }

thanks for helping

>Solution :

The reason why it not compile

Line 4 does not compile, since an abstract method cannot include a body.

Line 7 also does not compile because the wrong keyword is used. A class implements an interface