Plurals
There are seven ways to form plurals:
a. By adding s (Most words follow this rule.)
b. By adding es when the pronunciation requires it, such as s, ss, ch, sh, x.
c. By changing y to i and adding es when the final y is preceded by a consonant
(This rule is the same aforementioned rule (#7) for adding a suffix to words ending in y.)
d. By changing final f or fe to v and adding es (examples: scarves, calves).
e. By changing the internal vowels, as in foot, tooth, mouse, man.
f. A few words are spelled the same in both singular and plural (examples: deer, sheep).
g. A few words change the letters ending the word to form the plural
(examples: datum-data, radius-radi, gymnasium-gymnasia, phenomenon-phenomena,
criterion-criteria). These words are of foreign derivation and are not encountered
greatly by elementary-school children.
a. By adding s (Most words follow this rule.)
b. By adding es when the pronunciation requires it, such as s, ss, ch, sh, x.
c. By changing y to i and adding es when the final y is preceded by a consonant
(This rule is the same aforementioned rule (#7) for adding a suffix to words ending in y.)
d. By changing final f or fe to v and adding es (examples: scarves, calves).
e. By changing the internal vowels, as in foot, tooth, mouse, man.
f. A few words are spelled the same in both singular and plural (examples: deer, sheep).
g. A few words change the letters ending the word to form the plural
(examples: datum-data, radius-radi, gymnasium-gymnasia, phenomenon-phenomena,
criterion-criteria). These words are of foreign derivation and are not encountered
greatly by elementary-school children.