Comparing actions: faster, more quickly, most carefully
Short adverbs: -er/-est (faster, fastest) | Long adverbs: more/most + adverb
She doesn't run as fast as him. / less quickly
Who works harder?
💡 Short adverbs (fast, hard, early) add -er/-est. Long adverbs (-ly words) use more/most.
✓She speaks more fluently than her sister.
✗She speaks fluenter than her sister.
Long adverbs (fluently) use 'more', not -er.
✓He runs faster than anyone else.
✗He runs more fast than anyone else.
Short adverbs (fast) add -er, not 'more'.
✓She performed the best of all the candidates.
✗She performed the most well of all the candidates.
Well → better → best (irregular).