When my son was around three, he went through a period of assuming all nouns ending in "s" sounds were plurals. So, using three-year-old logic, he "depluralized" them. One slice of cheese was a "chee". One item of clothes was a "clo". One side of his nose was a "no".

He grew out of it, but I still jokingly call a slice of cheese a "chee" upon occasion.