One possible solution to the pig latin problem. It takes only lower cased words and a group of words.

pig_latin

def pig_latin(s)
  vowels = %w(a e i o u)
  words = s.split(' ')
  @new_sentence = String.new

  words.each_with_index do |w, i|
    if vowels.include? w[0]
      word = w + 'way'
      word = i == (words.count - 1) ? word : word + ' '

      @new_sentence << word

    else
      first_vowel = w.index(/[aeiou]/)
      word = w[first_vowel..-1] + w[0..(first_vowel - 1)]
      word = word + 'ay'
      word = i == (words.count - 1) ? word : word + ' '
   
      @new_sentence << word
    end
  end

  @new_sentence
end