A. After comparatives you can use than
A1. Comparative form is -er or more ~
A2. use -er: cheap -> cheaper, thin -> thinner, pretty -> prettier (-y -> ier for two-syllable word)
A3. use more for two syllable or more: more often, use more for adverbs that end in -ly: more seriously
A4. can use -er or more with some two-syllable adjectives: clever, narrow, quiet, shallow, simple

B. god/well -> better, bad/ badly -> worse, far -> further or farther, further also ‘more’ or ‘additional’