Слова cheap popular comfortable modern serious fast slow small full empty deep dirty в сравнительной и превосходной степени

Cheap cheaper the cheapest

Popular more popular the most popular

Comfortable more comfortable the most comfortable

Modern more modern the most modern

Serious more serious the most serious

Fast faster the fastest

Slow slower the slowest

Small smaller the smallest

Full, empty (absolute adjective) не имеют степеней сравнения

Deep deeper the deepest

Dirty dirtier the dirtiest