PRETTY
Julie is prettier than Emma.
pretty (shoes)
The white shoes are prettier than the black shoes.
ugly (dress)
The pink dress is uglier than the yellow dress.
clean (towel)
The white towel is cleaner than the yellow towel.
thick (socks)
The grey socks are thicker than the white socks.
dirty
The blue T-shirt is dirtier than the green T-shirt.
clean (pants)
The brown pants are cleaner than the blue pants.
dirty (jacket)
The blue jacket is dirtier than the black jacket.