Dictionary show action for letters, alphabetical links helper

app/controllers/dictionary_controller.rb

@@ -3,4 +3,9 @@ class DictionaryController < ApplicationController
     @parts_of_speech = PartOfSpeech.all
     @words = Word.all
   end
+
+  def show
+    @letter = params[:id]
+    @words = Word.where('substr(word, 1, 1) = ?', @letter)
+  end
 end