1) Her illness was MORE SERIOUS than we at first had thought.
2) Jim is not very tall. His brother Alec is TALLER.
3) I liked studying Chemistry very much; it is THE MOST INTERESTING subject for me.
4) Leo drives a car well, but Collin does it BETTER.
5) The days in summer are LONGER the days in winter.
6) My elder brother is three years OLDER than I.
7) I don't know much but he knows LESS than I do.
8) I can't walk very fast. You are younger; you can walk FASTER.
9) Are you good at tennis? I am THE WORST tennis player in the world.