Rules of a Quatrain :
Did you notice that a quatrain is formed by two rhyming couplets? Easy! This pattern is called a a b b. The first line rhymes with the second (sky and by) and the third line rhymes with the fourth line (edge and ledge). Other quatrain patterns are a b a b,
a b b a, and a b c b.
its a fun to try style when you dont want to spend too much time on rhyming or counting numbers of syllables. 🙂