The plural of hippopotamus is hippopotamuses, and hippopotami is also accepted in English.
Many people become confused because English uses words from different languages, and some keep their original plural forms while others follow regular English grammar.
In this guide, you will learn the correct plural forms of hippopotamus, where they came from, whether British and American English treat them differently, which form you should use in different situations, common mistakes to avoid, everyday examples, usage trends, helpful comparison tables, frequently asked questions, and practical tips for using the right form with confidence.
Quick Answer
The correct plural of hippopotamus is:
- Hippopotamuses ✅ (most common in modern English)
- Hippopotami ✅ (traditional and still accepted)
Both forms are correct.
Examples
- We saw three hippopotamuses at the zoo.
- The river is home to many hippopotami.
- Scientists study hippopotamuses in Africa.
In everyday English, hippopotamuses is the preferred choice because it follows normal English plural rules.
The Origin of Plural of Hippopotamus
The word hippopotamus comes from Ancient Greek.
- Hippos means horse.
- Potamos means river.
Together, the word means river horse.
The English word entered the language through Latin. Because of its classical roots, some people use the Latin-style plural hippopotami. However, modern English usually forms plurals by adding -es, creating hippopotamuses.
This is why both plural forms exist today. One follows traditional classical grammar, while the other follows modern English grammar.
British English vs American English Spelling
Unlike many spelling differences between British and American English, there is no spelling difference for the plural of hippopotamus.
Both British and American English accept:
- Hippopotamuses
- Hippopotami
However, modern style guides and dictionaries usually recommend hippopotamuses because it is clearer for most readers.
| British English | American English |
|---|---|
| Hippopotamuses (preferred) | Hippopotamuses (preferred) |
| Hippopotami (accepted) | Hippopotami (accepted) |
| Same spelling | Same spelling |
| Used in schools and publications | Used in schools and publications |
Which Spelling Should You Use?
Choose your plural based on your audience.
For American readers
Use hippopotamuses.
It matches standard English grammar and is the most common form.
For British readers
Use hippopotamuses in most writing.
Hippopotami is still acceptable, especially in academic or traditional writing.
For international audiences
Use hippopotamuses.
It is easier to understand and preferred by many editors and style guides.
Common Mistakes with Plural of Hippopotamus
Here are mistakes people often make.
| Incorrect | Correct |
|---|---|
| Hippopotamuses | Hippopotamuses |
| Hippopotamus | Hippopotamuses (when talking about more than one) |
| Hippopotamuss | Hippopotamus |
| Hippopotamii | Hippopotami |
| Hippopotamus’ | Hippopotamuses |
Correct Examples
- The hippopotamuses stayed in the water.
- Several hippopotami crossed the river.
- We watched the hippopotamuses eating grass.
Plural of Hippopotamus in Everyday Examples
The wildlife park now has four hippopotamuses.
News
The rescue team helped several hippopotamuses after flooding.
Social Media
The baby hippopotamuses are so cute!
School Writing
Students learned that hippopotamuses spend much of the day in water.
Scientific Writing
Researchers observed groups of hippopotami in their natural habitat.
Plural of Hippopotamus – Google Trends & Usage Data
Search interest for the plural of hippopotamus stays steady because students, writers, and English learners often search for the correct form.
General usage patterns include:
- United States: Hippopotamuses is more common.
- United Kingdom: Both forms appear, but hippopotamuses is slightly more frequent.
- Australia and Canada: Hippopotamuses is generally preferred.
- Academic writing: Hippopotami appears more often than in everyday writing.
Modern dictionaries and educational resources increasingly recommend hippopotamuses because it follows standard English plural rules.
Comparison Table
| Word | Correct | Notes |
|---|---|---|
| Hippopotamus | ✅ Singular | One animal |
| Hippopotamuses | ✅ Correct plural | Most common modern English |
| Hippopotami | ✅ Correct plural | Traditional classical plural |
| Hippopotamuses | ❌ Incorrect | Wrong spelling |
| Hippopotamii | ❌ Incorrect | Not an English plural |
FAQs
What is the correct plural of hippopotamus?
The correct plural is hippopotamuses. Hippopotami is also correct.
Is hippopotami grammatically correct?
Yes. It is a traditional plural based on classical language roots.
Which plural is more common today?
Hippopotamuses is more common in modern English.
Do British and American English use different plurals?
No. Both accept hippopotamuses and hippopotami.
Which form should students use?
Most teachers recommend hippopotamuses because it follows standard English grammar.
Is hippopotamuses correct?
No. The correct spelling is hippopotamuses.
Why are there two correct plural forms?
Because the word has Greek and Latin roots, English accepts both the classical plural and the regular English plural.
Conclusion
The plural of hippopotamus is hippopotamuses, while hippopotami is also correct and accepted in English.
The safest choice for most readers is hippopotamuses because it follows modern English grammar and is widely used in schools, dictionaries, news articles, and everyday writing.
If you are writing for a general audience, use hippopotamuses for the clearest communication. For academic or traditional contexts, hippopotami is also appropriate.
If you enjoyed this guide, you may also like our related article on plural of octopus to learn another commonly confused English plural.
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