diff --git a/core/object.rbs b/core/object.rbs
index b41c297..8feb2e3 100644
--- a/core/object.rbs
+++ b/core/object.rbs
@@ -55,11 +55,9 @@ class Object < BasicObject
   #        | (Exception, String message) -> bot
   #        | (singleton(Exception), String message) -> bot
 
-  # TODO: Symbol
-  # def self.attr_reader: (*String names) -> void
+  def self.attr_reader: (*Symbol names) -> void
 
-  # TODO: Symbol
-  # def self.attr_accessor: (*Symbol names) -> void
+  def self.attr_accessor: (*Symbol names) -> void
 
   def include: (Module, *Module mods) -> void
   def self.include: (Module, *Module mods) -> void
@@ -67,7 +65,7 @@ class Object < BasicObject
   alias extend include
   alias self.extend self.include
 
-  # TODO: Array, Symbol
+  # TODO: Array
   # def self.constants: (?bool inherit) -> Array[Symbol]
 
   def self.public: () -> void
diff --git a/core/string.rbs b/core/string.rbs
index 1abbd72..f114871 100644
--- a/core/string.rbs
+++ b/core/string.rbs
@@ -79,10 +79,9 @@ class String < Object
 
   def strip!: () -> self?
 
-  # TODO: Symbol
-  # def to_sym: () -> Symbol
-  #
-  # alias intern to_sym
+  def to_sym: () -> Symbol
+
+  alias intern to_sym
 
   def tr: (String pattern, String replace) -> String
 
diff --git a/core/symbol.rbs b/core/symbol.rbs
new file mode 100644
index 0000000..5299ba3
--- /dev/null
+++ b/core/symbol.rbs
@@ -0,0 +1,14 @@
+class Symbol < Object
+  # TODO: Array
+  # def self.all_symbols: () -> Array[Symbol]
+
+  def inspect: () -> String
+  def self.inspect: () -> String
+
+  def to_s: () -> String
+  def self.to_s: () -> String
+
+  alias id2name to_s
+
+  def to_sym: () -> Symbol
+end
diff --git a/test/object.rb b/test/object.rb
index 7914663..b0c2281 100644
--- a/test/object.rb
+++ b/test/object.rb
@@ -3,11 +3,13 @@
 # rubocop:disable Lint/Void
 # rubocop:disable Lint/UnreachableCode
 # rubocop:disable Lint/UselessAccessModifier
+# rubocop:disable Lint/DuplicateMethods
 # rubocop:disable Style/CaseEquality
 # rubocop:disable Style/ClassCheck
 # rubocop:disable Style/FormatString
 # rubocop:disable Style/RedundantFormat
 # rubocop:disable Style/MixinGrouping
+# rubocop:disable Style/AccessorGrouping
 # rubocop:disable Layout/EmptyLinesAroundAccessModifier
 
 # @type const TestMod: Module
@@ -82,6 +84,12 @@ module TestMod end
 
 # @type const A: Class
 class A
+  attr_reader :foo
+  attr_reader :foo, :bar, :baz
+
+  attr_accessor :foo
+  attr_accessor :foo, :bar, :baz
+
   # @type const TestMod: Module
   module TestMod end
 
diff --git a/test/string.rb b/test/string.rb
index ff41d9d..ae593cd 100644
--- a/test/string.rb
+++ b/test/string.rb
@@ -2,6 +2,7 @@
 
 # rubocop:disable Lint/Void
 # rubocop:disable Lint/RedundantTypeConversion
+# rubocop:disable Lint/SymbolConversion
 # rubocop:disable Style/StringConcatenation
 
 String.new
@@ -85,6 +86,10 @@
 
 ' abcdef '.strip!
 
+'abcdef'.to_sym
+
+'abcdef'.intern
+
 'abcdef'.tr 'a-z', 'n-za-m'
 
 'abcdef'.tr! 'a-z', 'n-za-m'
diff --git a/test/symbol.rb b/test/symbol.rb
new file mode 100644
index 0000000..a2b4dcf
--- /dev/null
+++ b/test/symbol.rb
@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+# rubocop:disable Lint/SymbolConversion
+# rubocop:disable Lint/RedundantTypeConversion
+
+:foo.inspect
+Symbol.inspect
+
+:foo.to_s
+Symbol.to_s
+
+:foo.id2name
+
+:foo.to_sym
+
+# rubocop:enable all