The noun list https://www.desiquintans.com/nounlist

The pluralizer https://github.com/plurals/pluralize https://pypi.org/project/pluralizer/

• behaves correctly when the plural is the same as the singular
• Just adds an 's' for singularia tantum nouns (so grammar model correctly identifies it as wrong)

print("Homework", end=" -> ")
print(pluralizer.pluralize("homework"))
print("Furniture", end=" -> ")
print(pluralizer.pluralize("furniture"))

# Homework -> homework
# Furniture -> furnitures

Inflections https://github.com/jaraco/inflect