diff --git a/lib/src/ilist/ilist.dart b/lib/src/ilist/ilist.dart
index c7ec2a1..3d2c861 100644
--- a/lib/src/ilist/ilist.dart
+++ b/lib/src/ilist/ilist.dart
@@ -18,7 +18,7 @@ import "l_flat.dart";
 @immutable
 class IListEmpty<T> // ignore: must_be_immutable
     extends IList<T> {
-  /// Creates a empty list. In most cases, you should use `const IList.empty()`.
+  /// Creates an empty list. In most cases, you should use `const IList.empty()`.
   ///
   /// IMPORTANT: You must always use the `const` keyword.
   /// It's always wrong to use an `IListEmpty()` which is not constant.
@@ -29,7 +29,7 @@ class IListEmpty<T> // ignore: must_be_immutable
   @override
   final ConfigList config;
 
-  /// A empty list is always flushed, by definition.
+  /// An empty list is always flushed, by definition.
   @override
   bool get isFlushed => true;
 
@@ -37,6 +37,14 @@ class IListEmpty<T> // ignore: must_be_immutable
   @override
   IListEmpty<T> get flush => this;
 
+  /// An empty list is always empty, by definition
+  @override
+  bool get isEmpty => true;
+
+  /// An empty list is always empty, by definition
+  @override
+  bool get isNotEmpty => false;
+
   @override
   int get _counter => 0;
 
diff --git a/lib/src/imap/imap.dart b/lib/src/imap/imap.dart
index bfa0e0f..d0237ca 100644
--- a/lib/src/imap/imap.dart
+++ b/lib/src/imap/imap.dart
@@ -19,7 +19,7 @@ import "m_replace.dart";
 @immutable
 class IMapEmpty<K, V> // ignore: must_be_immutable
     extends IMap<K, V> {
-  /// Creates a empty map. In most cases, you should use `const IMap.empty()`.
+  /// Creates an empty map. In most cases, you should use `const IMap.empty()`.
   ///
   /// IMPORTANT: You must always use the `const` keyword.
   /// It's always wrong to use an `IMapEmpty()` which is not constant.
@@ -30,7 +30,7 @@ class IMapEmpty<K, V> // ignore: must_be_immutable
   @override
   final ConfigMap config;
 
-  /// A empty map is always flushed, by definition.
+  /// An empty map is always flushed, by definition.
   @override
   bool get isFlushed => true;
 
@@ -38,6 +38,14 @@ class IMapEmpty<K, V> // ignore: must_be_immutable
   @override
   IMapEmpty<K, V> get flush => this;
 
+  /// An empty map is always empty, by definition
+  @override
+  bool get isEmpty => true;
+
+  /// An empty map is always empty, by definition
+  @override
+  bool get isNotEmpty => false;
+
   @override
   int get _counter => 0;
 
diff --git a/lib/src/iset/iset.dart b/lib/src/iset/iset.dart
index 84818ef..4a39203 100644
--- a/lib/src/iset/iset.dart
+++ b/lib/src/iset/iset.dart
@@ -18,7 +18,7 @@ import "s_flat.dart";
 @immutable
 class ISetEmpty<T> // ignore: must_be_immutable
     extends ISet<T> {
-  /// Creates a empty set. In most cases, you should use `const ISet.empty()`.
+  /// Creates an empty set. In most cases, you should use `const ISet.empty()`.
   ///
   /// IMPORTANT: You must always use the `const` keyword.
   /// It's always wrong to use an `ISetEmpty()` which is not constant.
@@ -29,7 +29,7 @@ class ISetEmpty<T> // ignore: must_be_immutable
   @override
   final ConfigSet config;
 
-  /// A empty set is always flushed, by definition.
+  /// An empty set is always flushed, by definition.
   @override
   bool get isFlushed => true;
 
@@ -37,6 +37,14 @@ class ISetEmpty<T> // ignore: must_be_immutable
   @override
   ISetEmpty<T> get flush => this;
 
+  /// An empty set is always empty, by definition
+  @override
+  bool get isEmpty => true;
+
+  /// An empty set is always empty, by definition
+  @override
+  bool get isNotEmpty => false;
+
   @override
   int get _counter => 0;
 
diff --git a/test/ilist/ilist_empty_test.dart b/test/ilist/ilist_empty_test.dart
index e4b06bf..18c7c14 100644
--- a/test/ilist/ilist_empty_test.dart
+++ b/test/ilist/ilist_empty_test.dart
@@ -72,4 +72,9 @@ void main() {
     expect(const IList.empty().equalItemsAndConfig(const IList.empty()), isTrue);
     expect(const IList.empty().equalItemsAndConfig(const IListEmpty()), isTrue);
   });
+
+  test(".isEmpty() | .isNotEmpty()", () {
+    expect(const IList.empty().isEmpty, isTrue);
+    expect(const IList.empty().isNotEmpty, isFalse);
+  });
 }
diff --git a/test/imap/imap_empty_test.dart b/test/imap/imap_empty_test.dart
index 6ad8b2e..41a6844 100644
--- a/test/imap/imap_empty_test.dart
+++ b/test/imap/imap_empty_test.dart
@@ -81,4 +81,9 @@ void main() {
     expect(const IMap.empty().equalItemsAndConfig(const IMap.empty()), isTrue);
     expect(const IMap.empty().equalItemsAndConfig(const IMapEmpty()), isTrue);
   });
+
+  test(".isEmpty() | .isNotEmpty()", () {
+    expect(const IMap.empty().isEmpty, isTrue);
+    expect(const IMap.empty().isNotEmpty, isFalse);
+  });
 }
diff --git a/test/iset/iset_empty_test.dart b/test/iset/iset_empty_test.dart
index 2890a3a..7eba763 100644
--- a/test/iset/iset_empty_test.dart
+++ b/test/iset/iset_empty_test.dart
@@ -72,4 +72,9 @@ void main() {
     expect(const ISet.empty().equalItemsAndConfig(const ISet.empty()), isTrue);
     expect(const ISet.empty().equalItemsAndConfig(const ISetEmpty()), isTrue);
   });
+
+  test(".isEmpty() | .isNotEmpty()", () {
+    expect(const ISet.empty().isEmpty, isTrue);
+    expect(const ISet.empty().isNotEmpty, isFalse);
+  });
 }