Count Number of Words on Each Sentence in Ruby

How do you count the words on each sentence if you have a bunch of sentences (a paragraph or two).

string = "hello world.  Hello world."

#I first split sentences into an element like so, first maybe initialized variables to count sentence, then words within the sentence
sentencecount = 0
wordcount = 0

string.split(".").each do |sentence|
  sentencecount += 1                     #track number of sentence
  sentence.(/\W+/).each do |word|
    wordcount += 1                       #to track number of word
  end

  puts "Sentence #{sentencecount} has #{wordcount} words."

end

Output:

Sentence 1 has 2 words
Sentence 2 has 5 words

Second line should say 2 words not 5. Any ideas? Yes two loops. Maybe there are better ways to do this but this is how I understand the program.