Сравнительная и превосходная степень глагола dirty.

dirty - dirtier - the dirtiest.

This shirt is dirty. Your shirt is dirtier than mine. This is the dirtiest shirt in the world.

I do not like dirty games. This game is dirtier than the previous game. It's the dirtiest thing that was in football.

My face is dirty. Your face is dirtier than mine. He has the dirtiest face.

I do not like dirty people. This man is dirtier than you. This is the dirtiest person in the world.

I think that the laundry is dirty. Your things are dirtier than mine. This person has the dirtiest things in school.