class Array

def to_sentence(options = {})

* :last_word_connector - The sign or word used to join the last element in arrays with three or more elements (default: ", and ")
* :two_words_connector - The sign or word used to join the elements in arrays with two elements (default: " and ")
* :words_connector - The sign or word used to join the elements in arrays with two or more elements (default: ", ")
Converts the array to a comma-separated sentence where the last element is joined by the connector word. Options: 
def to_sentence(options = {})
  if defined?(I18n)
    default_words_connector     = I18n.translate(:'support.array.words_connector',     :locale => options[:locale])
    default_two_words_connector = I18n.translate(:'support.array.two_words_connector', :locale => options[:locale])
    default_last_word_connector = I18n.translate(:'support.array.last_word_connector', :locale => options[:locale])
  else
    default_words_connector     = ", "
    default_two_words_connector = " and "
    default_last_word_connector = ", and "
  end
  options.assert_valid_keys(:words_connector, :two_words_connector, :last_word_connector, :locale)
  options.reverse_merge! :words_connector => default_words_connector, :two_words_connector => default_two_words_connector, :last_word_connector => default_last_word_connector
  case length
    when 0
      ""
    when 1
      self[0].to_s
    when 2
      "#{self[0]}#{options[:two_words_connector]}#{self[1]}"
    else
      "#{self[0...-1].join(options[:words_connector])}#{options[:last_word_connector]}#{self[-1]}"
  end
end