Examples

• absolution, absolved, absolve
• adoption, adopted, adopt
• engineering, engineered, engineers, engineer
• formalisms, formalism, formalities, formal
• hesitancy, hesitant, hesitate
• ponies, pony
• possessions, possesses, possess
• readings, reading, readable, readers, reader read
• statistical, statistics
• user, users, used, using, use

Complexities

• multiple dictionary entries: formalism, formal
• short words: kings, sings
• spelling variations: absorb, absorption; levelled, level; sing, song; woman, women