Nouns with the Same Singular and Plural Form

While many English nouns form their plural by adding “-s” or “-es,” some irregular nouns do not change at all. Here are some of the most important examples:

• aircraft, hovercraft, spacecraft, etc.
  “There are two aircraft prepared for landing.”
• bison
  “The bison were grazing in the distance.”
• cod
  “The cod are known to migrate in large numbers.”
• deer
  “Deer are an easy prey for wolves.”
• fish
  “Three fish swim in the fish tank.”
• moose
  “Moose actually belong to the deer family.”
• offspring
  “The fox gave birth to five offspring.”
• pike
  “The pike are big freshwater predatory fish.”
• salmon
  “Salmon are often seen jumping over dangerous waterfalls.”
• sheep
  “One sheep, two sheep, three sheep…”
• shrimp
  “Shrimp are among the most commonly eaten animals.”
• trout
  “The trout are fish related to the salmon.”

Note that many species of fish were left out from the list. Referring to fish using the same singular and plural form is extremely common, but actual usage varies somewhat among different regions, so it is advisable to consult a dictionary when writing about a particular species.

Plural Forms for Species

The names of animals mentioned above are sometimes used in the plural with an “-es” to refer to several different species bearing the same name. This helps distinguish a single type of animal from multiple types.

“The diversity of the reef’s fishes (fish species) is threatened by human activity.”

Nouns with Regular or Irregular Plural Forms

Some nouns can take either a regular or irregular plural form, depending on the context.

• boar/boars and swine/swines
  “We saw several boars.”
  “Swine are reared extensively in Europe.”
  “Those swines spilled their drinks on my couch.”

Adjectives Used as Plural Nouns

Many adjectives used to describe a nation or an ethnic group can be used as plural nouns (often with “the”). This is a way to refer to all the people from that group.

“The British are notorious in Europe for their terrible cuisine.”
“They could learn a lot from the French.”
“Nevertheless, most Chinese enjoy a different kind of cuisine.”