Plural of 'calf' is _____________.

Answer: calves

Rule: For many nouns that end in -f or -fe, form the plural by replacing -f/-fe with -ves.

• Apply the rule: drop the final -f or -fe and add -ves. Example: calf → calves; knife → knives.

• Exceptions: Some nouns ending in -f simply take -s in the plural. Examples: chief → chiefs; roof → roofs; belief → beliefs; chef → chefs.

• Singular vs plural note: 'calf' is singular; the plural form is 'calves'.

Therefore, the correct plural of calf is 'calves'.