AMA Manual of Style - Stacy L. Christiansen, Cheryl Iverson 2020
How Plurals Are Formed
Plurals
The plurals of most nouns are formed by adding s or es (Table 9.1-1).
Table 9.1-1. Noun Plurals
Singular |
Plural |
benefit |
benefits |
cervix |
cervixes |
correction |
corrections |
disease |
diseases |
guideline |
guidelines |
method |
methods |
inch |
inches |
However, English is irregular enough that many exceptions exist (Table 9.1-2).
Table 9.1-2. Exceptions to Noun Plurals
Singular |
Plural |
child |
children |
foot |
feet |
metastasis |
metastases |
louse |
lice |
offspring |
offspring |
sty |
sties |
tooth |
teeth |
woman |
women |
species |
species |