Prefix + Free Base + Suffix + Suffix = re + view + er + s
5. The final <e> deletion is crucial. Clothing is formed from the verb clothe, not from the noun cloth.
Questions to ask: Why the -es in churches and princesses, but -s in unions, picnics, and reviewers? Why does the <c> in princesses spell [s] while the ones in picnics spell [k]? Why the difference in the way −s is pronounced in unions and picnics? If you were to make grandfather into a plural, which suffix would you add and how would it be pronounced—and why?