What’s the Plural of Hippopotamus? Is it Hippopotamuses?

The plural of hippopotamus refers to the form used when talking about more than one of these large, river-dwelling mammals. While many English nouns simply add an “-s” or “-es” to become plural, the word hippopotamus has sparked curiosity due to its Greek origins and unusual ending. The most commonly accepted plural is hippopotamuses, but hippopotami also appears occasionally, adding a layer of linguistic intrigue to the conversation about these majestic creatures.

Few animal names capture the imagination quite like hippopotamus. Their massive size, unpredictable behavior, and almost prehistoric appearance make them fascinating subjects in both language and nature. This combination of linguistic curiosity and animal intrigue draws in readers eager to understand the correct terminology while also discovering fascinating facts about the creatures themselves. It’s a delightful blend of language and wildlife that keeps people hooked.

Hippopotamuses are among the largest and most powerful mammals found in Africa, often spending their days submerged in rivers and lakes. Known for their surprisingly aggressive nature and unique adaptations, such as their nearly hairless bodies and enormous mouths, hippos have captured human fascination for centuries. Their name, derived from Greek meaning “river horse,” perfectly encapsulates their semi-aquatic lifestyle and adds to the rich cultural and linguistic story behind this extraordinary animal.

The Complete Answer: Hippopotamus Pluralization Rules

When discussing more than one hippopotamus, you have two perfectly acceptable options. The plural of hippopotamus can be either “hippopotamuses” or “hippopotami,” and here’s why both work.

Modern English strongly favors “hippopotamuses.” This form follows standard English grammar rules for pluralization, simply adding “-es” to words ending in “s.” It’s the form you’ll encounter most frequently in contemporary writing, from National Geographic articles to zoo educational materials.

“Hippopotami” represents the classical approach. This Latin plural form honors the word’s ancient roots. While less common today, it remains grammatically sound and appears in academic texts, scientific journals, and formal writing contexts.

Plural Form	Usage Context	Frequency	Preference
Hippopotamuses	General writing, journalism	75%	Modern English
Hippopotami	Academic, formal writing	25%	Classical Latin

The choice between these forms often depends on your audience and writing style. Casual speech vs formal speech considerations play a significant role in determining which plural sounds more natural.

Etymology Deep Dive: Where “Hippopotamus” Comes From

Understanding the word origin reveals why we have two plural options. The term hippopotamus comes from ancient Greek, combining “hippos” (meaning horse) and “potamos” (meaning river). Ancient Greeks literally called this massive creature a “river horse.”

When Romans encountered this Greek term, they adopted it into Latin as “hippopotamus.” This language borrowing process created the foundation for our modern pluralization debate. Latin typically formed plurals by changing “-us” endings to “-i,” giving us “hippopotami.”

English borrowed countless words from Latin, creating ongoing tension between standard plural rules and classical forms. The hippopotamus represents a perfect example of this linguistic tug-of-war.

Word derivation experts note that English has consistently moved toward regularized plurals. While “hippopotami” honors the etymology of the word, “hippopotamuses” reflects how English grammar rules naturally evolve.

Grammar Rules That Apply

Pluralization in English follows predictable patterns, but irregular plurals from foreign languages complicate matters. The hippopotamus plural situation illustrates broader principles of morphology in English.

Most English words ending in “-s” form plurals by adding “-es.” Following this rule gives us “hippopotamuses.” This approach demonstrates grammatical correctness according to modern English grammar rules.

However, Latin-derived words often retain their classical plural forms. Words like “alumnus/alumni” and “cactus/cacti” show similar patterns. The hippopotamus can follow either English or Latin rules without violating grammar standards.

Style guides vary in their recommendations:

• AP Stylebook: Prefers “hippopotamuses”
• Chicago Manual of Style: Accepts both forms
• Oxford Style Guide: Favors “hippopotamuses” for general writing

Academic writing often leans toward “hippopotami” to demonstrate classical knowledge, while journalism and casual speech favor “hippopotamuses” for clarity and accessibility.

“Hippo” vs. “Hippopotamus”: Usage Distinctions

The shortened form “hippo” eliminates plural confusion entirely. What’s the plural of hippo? Simply “hippos” – no debate required. This lexical variation shows how language naturally simplifies complex forms.

Formal writing contexts typically require the full term hippopotamus. Scientific papers, academic research, and official documents rarely use the casual “hippo” form. The distinction between common vs. scientific naming becomes crucial here.

Children’s books and educational materials often prefer “hippos” for readability. Young readers grasp “hippos” more easily than either hippopotamus plural form. This demonstrates how spoken vs. written English considerations influence word choice.

Zoo signage reveals interesting patterns. Major facilities like the San Diego Zoo primarily use “hippos” in visitor materials while employing “hippopotamuses” in educational content. This semantic equivalence allows institutions to match their audience’s needs.

The hippopotamus remains the preferred term in animal classification systems and scientific literature. Zoologists studying these African mammals consistently use the full scientific name in research contexts.

Real-World Usage Examples

National Geographic predominantly uses “hippopotamuses” in their wildlife documentaries and articles. Their editorial team chose this form for consistency with modern English grammar rules and reader accessibility.

Scientific journals show mixed preferences. Journal of Mammalogy articles contain both “hippopotamuses” and “hippopotami,” often within the same publication. Authors typically maintain consistency within individual papers.

The Smithsonian National Zoo uses “hippos” in visitor signage but “hippopotamuses” in detailed educational materials. This approach balances accessibility with formal accuracy.

BBC Wildlife documentaries favor “hippopotamuses” in narration, aligning with their house style guidelines. David Attenborough’s programs consistently use this modern plural form.

Children’s nature books overwhelmingly choose “hippos” for plural references. Publishers recognize that young readers connect more easily with shorter word forms.

Collective Nouns: Groups of Hippos

When multiple hippopotamus individuals gather, specific collective nouns apply depending on location and behavior. These terms add precision to wildlife writing and conversation.

A “pod” of hippos describes the most common grouping. These river-dwelling animals form pods when wallowing in water together. The term “pod” emphasizes their aquatic nature and social behavior patterns.

A “bloat” of hippos refers to groups on land. This collective noun captures the impressive bulk these herbivorous mammals display when grazing together. Safari guides often use this term during game drives.

A “herd” serves as the generic collective term. When you’re unsure whether hippos are in water or on land, “herd” works universally. It’s the safest choice for general writing about hippopotamus groups.

Collective Noun	Context	Usage Example
Pod	In water	“A pod of hippos wallowed in the river”
Bloat	On land	“The bloat of hippos grazed near the riverbank”
Herd	General use	“A herd of hippos dominated the watering hole”

Understanding these collective noun examples enhances wildlife writing accuracy and demonstrates knowledge of animal classification terminology.

Common Mistakes to Avoid

Mixing singular and plural forms within sentences creates confusion. Never write “The hippopotamus are grazing” or “Several hippopotamus emerged from the water.” Maintain consistency throughout your writing.

Possessive errors occur frequently with both plural forms. “Hippopotamuses'” and “hippopotami’s” both need apostrophes after the final “s” or “i” respectively. The grammatical correctness principle applies regardless of which plural you choose.

Overcorrecting happens when writers assume one form is wrong. Some people mistakenly believe “hippopotamuses” sounds uneducated, leading them to force “hippopotami” into inappropriate contexts. Both forms deserve respect.

Pronunciation mistakes plague both plurals. “Hippopotamuses” requires four syllables: hip-po-POT-a-mus-es. “Hippopotami” needs five: hip-po-POT-a-MY. Practice saying both forms aloud.

Context mismatching occurs when formal writing uses casual terms or vice versa. Match your hippopotamus plural choice to your audience and publication standards.

Expert Opinions and Style Guides

Merriam-Webster Dictionary lists “hippopotamuses” as the primary plural, with “hippopotami” as an accepted alternative. This hierarchy reflects modern English grammar rules preferences while acknowledging classical traditions.

Oxford English Dictionary provides extensive etymology information, explaining both plural forms’ legitimacy. Their historical approach validates the language borrowing process that created this dual system.

Linguistic authorities generally favor “hippopotamuses” for contemporary writing. Dr. Patricia O’Conner, grammar expert and author, states: “Modern English trends toward regularized plurals, making ‘hippopotamuses’ the safer choice for most writers.”

Educational institutions show varied approaches. Harvard’s writing center recommends consistency within documents while accepting both forms. Yale’s style guide suggests matching your field’s conventions – scientific writers might prefer “hippopotami” while journalists choose “hippopotamuses.”

Publishing houses increasingly standardize on “hippopotamuses.” Random House, Penguin, and HarperCollins style guides all favor the English plural for general audiences.

Practical Writing Applications

Audience consideration drives hippopotamus plural selection. Academic papers targeting classical scholars might benefit from “hippopotami,” while blog posts for general readers work better with “hippopotamuses.”

Genre-specific choices matter significantly. Nature writing, travel blogs, and educational content typically favor “hippopotamuses” for accessibility. Scholarly articles in animal classification or etymology might lean toward “hippopotami.”

International communication considerations affect global English usage. Non-native speakers often find “hippopotamuses” easier to understand and pronounce, making it preferable for international publications.

Consistency within documents trumps abstract correctness. Choose one plural form and maintain it throughout your piece. Readers notice inconsistency more than specific plural choices.

Brand voice alignment influences corporate writing. Zoo websites, nature magazines, and educational publishers should match their established tone and style preferences.

Quick Reference Guide

Decision flowchart for hippopotamus plurals:

1. Academic/scientific context? → Consider “hippopotami”
2. General audience? → Use “hippopotamuses”
3. Children’s content? → Choose “hippos”
4. Formal document? → Either form works; maintain consistency
5. Casual writing? → “Hippopotamuses” or “hippos”

Memory tricks:

• “Hippopotamuses” follows regular English patterns
• “Hippopotami” honors Latin tradition
• Both forms appear in major dictionaries
• Consistency matters more than specific choice

Writing Context	Recommended Plural	Reasoning
News articles	Hippopotamuses	Modern, accessible
Scientific papers	Either form	Field conventions vary
Children’s books	Hippos	Simplest option
Travel writing	Hippopotamuses	Contemporary standard
Academic essays	Hippopotami or Hippopotamuses	Depends on institution

Frequently Asked Questions

Is “hippopotami” grammatically incorrect?

No, “hippopotami” is perfectly correct. This Latin plural form has centuries of usage history and appears in major dictionaries. While less common today, it remains grammatically sound and appropriate for formal writing contexts.

Which plural should I use in academic writing?

Both “hippopotamuses” and “hippopotami” work in academic contexts. Check your institution’s style guide and field conventions. Scientific journals in animal classification may prefer “hippopotami,” while education papers might favor “hippopotamuses.”

Do zoos and aquariums prefer one form over another?

Most major zoos use “hippos” in visitor materials and “hippopotamuses” in educational content. The Bronx Zoo, San Diego Zoo, and National Aquarium all follow this pattern, prioritizing accessibility while maintaining scientific accuracy.

Are there other animals with similar plural confusion?

Yes! Irregular plurals from Latin and Greek origins create similar situations. Consider “octopus” (octopuses/octopi), “platypus” (platypuses/platypi), and “rhinoceros” (rhinoceroses/rhinoceri). The hippopotamus joins this group of morphology puzzles.

Will using the “wrong” plural hurt my credibility?

Neither plural form is wrong, so your credibility remains intact regardless of choice. However, context mismatching can affect perception. Using “hippopotami” in casual blog posts might seem pretentious, while “hippopotamuses” in classical studies could appear informal.

Embrace Both Forms: Your Path Forward

The plural of hippopotamus question has a satisfying answer: both “hippopotamuses” and “hippopotami” are correct. This grammatical correctness gives writers flexibility to match their audience and context.

Modern English increasingly favors “hippopotamuses” for its accessibility and alignment with standard plural rules. This trend reflects how language naturally evolves toward simplification and consistency.

Classical tradition keeps “hippopotami” alive in formal and academic contexts. Honoring the etymology and Latin heritage of the hippopotamus serves important scholarly purposes.

Your choice between these word forms should reflect your audience’s needs and expectations. Casual speech situations call for “hippopotamuses” or even “hippos,” while formal written English can accommodate either classical or modern plurals.

Remember that semantic equivalence means both plurals carry identical meaning. Whether you write about “hippopotamuses” wallowing in African rivers or “hippopotami” demonstrating their massive size, you’re communicating the same essential information about these remarkable river-dwelling animals.

The hippopotamus represents more than just a pluralization puzzle – it embodies the rich language borrowing history that makes English so wonderfully complex. Embrace both plural forms as legitimate expressions of this linguistic heritage.

Choose confidently, write consistently, and remember that clarity always trumps correctness debates. Your readers care more about understanding these magnificent African mammals than about which hippopotamus plural you select.