diff --git a/ext/readline/README b/ext/readline/README
index 1eb1f8bb64..9bbf325c99 100644
--- a/ext/readline/README
+++ b/ext/readline/README
@@ -11,17 +11,18 @@ Example:
 
 <module function>
 
-readline(prompt, add_hostory=nil)
+readline(prompt, add_history=nil)
 
-  Reads one line wit line edit.  the line is added to the
-  history also if "add" is true.
+  Reads one line with line editing.  The inputted line is added to the
+  history if add_history is true.
 
-<class mehods>
+<class methods>
 
 completion_proc = proc
 
-  Specifies Proc object to determin completion behavior.  It
-  shoule take input-string, and return completion candidates.
+  Specifies a Proc object to determine completion behavior.  It
+  should take input-string, and return an array of completion
+  candidates.
 
 completion_proc
 
@@ -37,12 +38,13 @@ completion_case_fold
 
 completion_append_character = char
 
-  Specifies a chacatcter to be appended on completion.
-  Nothing will be appended if empty string ("") or nil is specified.
+  Specifies a character to be appended on completion.
+  Nothing will be appended if an empty string ("") or nil is
+  specified.
 
 completion_append_character
 
-  Returns a string contains a character to be appended on
+  Returns a string containing a character to be appended on
   completion.  The default is a space (" ").
 
 vi_editing_mode
diff --git a/ext/readline/README.jp b/ext/readline/README.jp
index e342ca4300..beb951fbf0 100644
--- a/ext/readline/README.jp
+++ b/ext/readline/README.jp
@@ -11,10 +11,10 @@ line = readline("Prompt> ", true)
 
 <モジュール関数>
 
-readline(prompt, add=nil)
+readline(prompt, add_history=nil)
 
   一行入力を読み込みます。
-  addがtrueの場合、ヒストリに読み込んだ文字列を追加します。
+  add_historyがtrueの場合、ヒストリに読み込んだ文字列を追加します。
 
 <クラスメソッド>