many things, comments working.

config/locales/en.yml

@@ -2,4 +2,7 @@
 # See https://github.com/svenfuchs/rails-i18n/tree/master/rails%2Flocale for starting points.
 
 en:
-  hello: "Hello world"
+  simple_form:
+      required:
+        text: 'required'
+        mark: ''

config/locales/simple_form.en.yml

@@ -0,0 +1,25 @@
+en:
+  simple_form:
+    "yes": 'Yes'
+    "no": 'No'
+    required:
+      text: 'required'
+      mark: ''
+      # You can uncomment the line below if you need to overwrite the whole required html.
+      # When using html, text and mark won't be used.
+      html: ''
+    error_notification:
+      default_message: "Please fill out all required fields:"
+    # Labels and hints examples
+    # labels:
+    #   defaults:
+    #     password: 'Password'
+    #   user:
+    #     new:
+    #       email: 'E-mail to sign in.'
+    #     edit:
+    #       email: 'E-mail.'
+    # hints:
+    #   defaults:
+    #     username: 'User name to sign in.'
+    #     password: 'No special characters, please.'