```ruby
class TwoWordSentenceGenerator < SentenceGenerator
  def generate(wordcount)
    sentence = []
    x, y = random_word.split
    sentence << x << y
    (wordcount-1).times do
      sentence << weighted_random("#{sentence[sentence.length-2]} #{sentence.last}")
    end
    sentence.join(' ')
  end
end
```

Use concat on split words for sentence
user
```ruby
require_relative 'sentence-generator'

class TwoWordSentenceGenerator < SentenceGenerator
  def generate(wordcount)
    sentence = []
    sentence.concat(random_word.split)
    (wordcount-1).times do
      sentence.concat(weighted_random(sentence.last(2).join(' ')).split)
    end
    sentence.join(' ')
  end
end
```
assistant