Original: His novel Ender's Game (1985) and its sequel Speaker for the Dead (1986) both won Hugo and Nebula Awards, making Card the only author to win both of American science fiction's top prizes in consecutive years.
Simplified: His novel Ender's Game and its sequel Speaker for the Dead both won the Hugo Award and the Nebula Award, making Card the only writer (as of 2007) to win both of science fiction's top prizes two years in a row.