diff --git a/client/src/pages/guide/english/java/abstract-class/index.md b/client/src/pages/guide/english/java/abstract-class/index.md
index 75aaff22f0..388ba6c2f1 100644
--- a/client/src/pages/guide/english/java/abstract-class/index.md
+++ b/client/src/pages/guide/english/java/abstract-class/index.md
@@ -46,3 +46,4 @@ Car carObj = new Car();  // valid
 Motorcycle mBikeObj = new Motorcycle();  // valid
 ```
 
+If the child class doesn't implement the abstract methods of the father, it becomes an abstract class.