Its a sonnet that uses a ABAB pattern, this type of writing was usually used for love peoms in the elizabethan era so shakespeare using this frames tradgedy as a juxtaposition of love.
"I defy you stars!"
"Oh i am fortunes fool!
"My grave is like to be my wedding bed"
"some consequence yet hanging in the stars"
"Star-cross'dlovers take their life"
"The fearful passage of their death - mark'd love"
