Ответ:
Old- older- the oldest
Far- farther- the farthest (по расстоянию)
Far - further - the furthest (по времени)
Careful- more careful- the most careful
Nice- nicer- the nicest
Dirty-dirtier- the dirtiest
Popular- more popular- the most popular
Fat-fatter- the fattest
Little- less- the least
Thick- thicker- the thickest
Comfortable- more comfortable- the most comfortable