Shopper is an agent, not a comparative. Many of the words ending in -er are comparative because they are based on a comparison like big, bigger, biggest, fast, faster, fastest. But when the word changes from an action to a person or noun then it is an agent like shopper, editor, creator, etc.
Brighter
agent
a male shopper = koneh (×§×•× ×”) a female shopper = konah (×§×•× ×”)
"Litter" is a noun and a verb and, as such, does not have a comparative degree.
A comparative for the word ineffectual is more ineffectual.
smoother is comparative of word smooth.
The comparative is hotter.
comparative
Sharper is the comparative form of the word sharp.
comparative
comparative
Worse is the comparative word.
The comparative form of the word 'fast' is 'faster'.