Adverbs can have comparative forms to show how differently things happen.
Could you speak more quietly, please?
It’s Sunday, so Pete can get up later.
Jack drives better than his brother.
To make comparative forms of most adverbs, use ‘more’ or ‘less’ + adverb (…than):
People can cycle more safely on special cycling roads.
You should prepare for your exams more seriously than you do now.
Tommy did his homework less accurately than Mary.
Jacks talks to people less politely than Ben.
Adverbs ‘well’ and ‘badly’ have the same irregular comparative forms as the adjectives ‘good’ and ‘bad’:
good → well → I can cook better than you.
bad → badly → Sally sings worse than her sister Emily.
Some short adverbs, like ‘early’, ‘fast’, ‘slow’, ‘hard’, ‘high’, ‘long’, have comparative forms of adjectives with ‘-er’ at the end:
Turtles move slower than hedgehogs.
I came to the office earlier than my colleagues.
Timothy always runs faster than his friends.
Kate works harder than you, so please be more friendly to her.