For short adjectives ending in a consonant like "cold," "black," or "fast," one adds the suffix er to make a comparison of greater magnitude. Example: "The North Pole is colder than Florida." The greatest possible comparison is made by adding the suffix est. Example: "The North Pole is the coldest place on the Earth." For long adjectives like intelligent, conscientious, comprehensive, one uses the word more to make a comparison of greater magnitude. Example: "Children are more intelligent than adults." 