diff --git a/ChangeLog b/ChangeLog
index 2c682456c6..55e3d8ce3d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Sat Feb  8 03:57:32 2003  Akinori MUSHA  <knu@iDaemons.org>
+
+	* lib/irb/workspace.rb, lib/irb/ext/math-mode.rb,
+	  lib/irb/ext/multi-irb.rb, lib/irb/lc/error.rb,
+	  lib/irb/lc/help-message, lib/irb/lc/ja/error.rb,
+	  lib/shell/command-processor.rb, lib/shell/error.rb,
+	  lib/shell/filter.rb: Fix typos and grammos. [approved by: keiju]
+
 Sat Feb  8 03:34:28 2003  Akinori MUSHA  <knu@iDaemons.org>
 
 	* intern.h (HAVE_RB_DEFINE_ALLOC_FUNC): New boolean macro to make
diff --git a/lib/irb/ext/math-mode.rb b/lib/irb/ext/math-mode.rb
index a98664448e..5e268bb3e5 100644
--- a/lib/irb/ext/math-mode.rb
+++ b/lib/irb/ext/math-mode.rb
@@ -18,7 +18,7 @@ module IRB
 
     def math_mode=(opt)
       if @math_mode == true && opt == false
-	IRB.fail CantRetuenNormalMode
+	IRB.fail CantReturnToNormalMode
 	return
       end
 
diff --git a/lib/irb/ext/multi-irb.rb b/lib/irb/ext/multi-irb.rb
index 86569ae333..e815889383 100644
--- a/lib/irb/ext/multi-irb.rb
+++ b/lib/irb/ext/multi-irb.rb
@@ -9,7 +9,7 @@
 #
 #   
 #
-IRB.fail CanNotGoMultiIrbMode unless defined?(Thread)
+IRB.fail CantShiftToMultiIrbMode unless defined?(Thread)
 require "thread"
 
 module IRB
@@ -54,7 +54,7 @@ module IRB
     def switch(key)
       th, irb = search(key)
       IRB.fail IrbAlreadyDead unless th.alive?
-      IRB.fail IrbSwitchToCurrentThread if th == Thread.current
+      IRB.fail IrbSwitchedToCurrentThread if th == Thread.current
       @current_job = irb
       th.run
       Thread.stop
diff --git a/lib/irb/lc/error.rb b/lib/irb/lc/error.rb
index a80da7567f..27d151f98f 100644
--- a/lib/irb/lc/error.rb
+++ b/lib/irb/lc/error.rb
@@ -17,13 +17,13 @@ module IRB
   extend Exception2MessageMapper
   def_exception :UnrecognizedSwitch, "Unrecognized switch: %s"
   def_exception :NotImplementError, "Need to define `%s'"
-  def_exception :CantRetuenNormalMode, "Can't return normal mode."
+  def_exception :CantReturnToNormalMode, "Can't return to normal mode."
   def_exception :IllegalParameter, "Illegal parameter(%s)."
   def_exception :IrbAlreadyDead, "Irb is already dead."
-  def_exception :IrbSwitchToCurrentThread, "Change to current thread."
+  def_exception :IrbSwitchedToCurrentThread, "Switched to current thread."
   def_exception :NoSuchJob, "No such job(%s)."
-  def_exception :CanNotGoMultiIrbMode, "Can't go multi irb mode."
-  def_exception :CanNotChangeBinding, "Can't change binding to (%s)."
+  def_exception :CantShiftToMultiIrbMode, "Can't shift to multi irb mode."
+  def_exception :CantChangeBinding, "Can't change binding to (%s)."
   def_exception :UndefinedPromptMode, "Undefined prompt mode(%s)."
 
 end
diff --git a/lib/irb/lc/help-message b/lib/irb/lc/help-message
index 29c7c0fe4a..42e861a343 100644
--- a/lib/irb/lc/help-message
+++ b/lib/irb/lc/help-message
@@ -10,25 +10,25 @@
 #   
 #
 Usage:  irb.rb [options] [programfile] [arguments]
-  -f		    suppress read ~/.irbrc 
-  -m		    bc mode (load mathn, fraction or matrix are available)
-  -d                set $DEBUG  to true (same as `ruby -d')
-  -r load-module    same as `ruby -r'
-  --inspect	    uses `inspect' for output (the default except bc mode)
-  --noinspect	    doesn't uses inspect for output
-  --readline	    uses Readline extension module
-  --noreadline	    doesn't use Readline extension module
+  -f		    Suppress read of ~/.irbrc 
+  -m		    Bc mode (load mathn, fraction or matrix are available)
+  -d                Set $DEBUG to true (same as `ruby -d')
+  -r load-module    Same as `ruby -r'
+  --inspect	    Use `inspect' for output (default except for bc mode)
+  --noinspect	    Don't use inspect for output
+  --readline	    Use Readline extension module
+  --noreadline	    Don't use Readline extension module
   --prompt prompt-mode
   --prompt-mode prompt-mode
-		    switches prompt mode. Pre-defined prompt modes are
+		    Switch prompt mode. Pre-defined prompt modes are
 		    `default', `simple', `xmp' and `inf-ruby'
-  --inf-ruby-mode   uses prompt appreciate for inf-ruby-mode on emacs. 
+  --inf-ruby-mode   Use prompt appropriate for inf-ruby-mode on emacs. 
 		    Suppresses --readline. 
-  --simple-prompt   simple prompt mode
-  --noprompt	    no prompt
-  --tracer	    display trace for each execution of commands.
+  --simple-prompt   Simple prompt mode
+  --noprompt	    No prompt mode
+  --tracer	    Display trace for each execution of commands.
   --back-trace-limit n
-		    displayes backtrace top n and tail n. The default
+		    Display backtrace top n and tail n. The default
 		    value is 16. 
-  --irb_debug n	    sets internal debug level to n (It shouldn't be used)
-  -v, --version	    prints the version of irb
+  --irb_debug n	    Set internal debug level to n (not for popular use)
+  -v, --version	    Print the version of irb
diff --git a/lib/irb/lc/ja/error.rb b/lib/irb/lc/ja/error.rb
index 19585467a0..42493554c6 100644
--- a/lib/irb/lc/ja/error.rb
+++ b/lib/irb/lc/ja/error.rb
@@ -16,13 +16,13 @@ module IRB
   extend Exception2MessageMapper
   def_exception :UnrecognizedSwitch, 'スイッチ(%s)が分りません'
   def_exception :NotImplementError, '`%s\'の定義が必要です'
-  def_exception :CantRetuenNormalMode, 'Normalモードに戻れません.'
+  def_exception :CantReturnToNormalMode, 'Normalモードに戻れません.'
   def_exception :IllegalParameter, 'パラメータ(%s)が間違っています.'
   def_exception :IrbAlreadyDead, 'Irbは既に死んでいます.'
-  def_exception :IrbSwitchToCurrentThread, 'Change to current thread.'
+  def_exception :IrbSwitchedToCurrentThread, 'カレントスレッドに切り替わりました.'
   def_exception :NoSuchJob, 'そのようなジョブ(%s)はありません.'
-  def_exception :CanNotGoMultiIrbMode, 'multi-irb modeに移れません.'
-  def_exception :CanNotChangeBinding, 'バインディング(%s)に変更できません.'
+  def_exception :CantShiftToMultiIrbMode, 'multi-irb modeに移れません.'
+  def_exception :CantChangeBinding, 'バインディング(%s)に変更できません.'
   def_exception :UndefinedPromptMode, 'プロンプトモード(%s)は定義されていません.'
 end
 
diff --git a/lib/irb/workspace.rb b/lib/irb/workspace.rb
index 6dcb450fd7..3659fa8b56 100644
--- a/lib/irb/workspace.rb
+++ b/lib/irb/workspace.rb
@@ -67,7 +67,7 @@ EOF
 	  begin 
 	    @binding = eval("IRB.conf[:__MAIN__].instance_eval('binding', __FILE__, __LINE__)", @binding, __FILE__, __LINE__)
 	  rescue TypeError
-	    IRB.fail CanNotChangeBinding, @main.inspect
+	    IRB.fail CantChangeBinding, @main.inspect
 	  end
 	end
       end
diff --git a/lib/shell/command-processor.rb b/lib/shell/command-processor.rb
index 79310359e6..0c65d3be36 100644
--- a/lib/shell/command-processor.rb
+++ b/lib/shell/command-processor.rb
@@ -277,7 +277,7 @@ class Shell
       when IO
 	AppendIO.new(@shell, to, filter)
       else
-	Shell.Fail CanNotMethodApply, "append", to.class
+	Shell.Fail CantApplyMethod, "append", to.class
       end
     end
 
diff --git a/lib/shell/error.rb b/lib/shell/error.rb
index df5e669af6..d338b1c5d1 100644
--- a/lib/shell/error.rb
+++ b/lib/shell/error.rb
@@ -18,8 +18,8 @@ class Shell
     def_e2message TypeError, "wrong argument type %s (expected %s)"
 
     def_exception :DirStackEmpty, "Directory stack empty."
-    def_exception :CanNotDefine, "Can't define method(%s, %s)."
-    def_exception :CanNotMethodApply, "This method(%s) can't apply this type(%s)."
+    def_exception :CantDefine, "Can't define method(%s, %s)."
+    def_exception :CantApplyMethod, "This method(%s) does not apply to this type(%s)."
     def_exception :CommandNotFound, "Command not found(%s)."
   end
 end
diff --git a/lib/shell/filter.rb b/lib/shell/filter.rb
index 727826b7c9..4cf793a3b3 100644
--- a/lib/shell/filter.rb
+++ b/lib/shell/filter.rb
@@ -47,7 +47,7 @@ class Shell
 	self.input = src
 	self
       else
-	Filter.Fail CanNotMethodApply, "<", to.class
+	Filter.Fail CantApplyMethod, "<", to.class
       end
     end
 
@@ -63,7 +63,7 @@ class Shell
       when IO
 	each(){|l| to << l}
       else
-	Filter.Fail CanNotMethodApply, ">", to.class
+	Filter.Fail CantApplyMethod, ">", to.class
       end
       self
     end
@@ -71,8 +71,8 @@ class Shell
     def >> (to)
       begin
 	Shell.cd(@shell.pwd).append(to, self)
-      rescue CanNotMethodApply
-	Shell.Fail CanNotMethodApply, ">>", to.class
+      rescue CantApplyMethod
+	Shell.Fail CantApplyMethod, ">>", to.class
       end
     end