What’s the Plural of Genus: Understanding Scientific Terminology
Quick Answer
The plural of genus is genera or genuses. Both are correct. Use genera in science and formal writing. Use genuses in everyday English.
Genera and Genuses — See How They Work
The word genus comes from Latin. That is why it has two plural forms. Look at these examples:
- The biology book lists many plant genera. (science writing)
- My teacher said cats and dogs belong to different genuses. (everyday English)
- Scientists have named over 500,000 genera of living things. (scientific)
- There are many rose genuses in this garden. (everyday talk)
Did you see the pattern? Genera appears in books, biology, and formal writing. Genuses sounds natural in normal conversations.
| Singular | Plural (formal/science) | Plural (everyday) |
|---|---|---|
| genus | genera | genuses |
When to Use Genera and When to Use Genuses
The rule is simple. Think about who you are talking to.
Use “genera” when:
- You are writing for a biology or science class
- You are reading or writing an academic paper
- You want to sound scientific — this is what most experts use
Use “genuses” when:
- You are chatting with friends or family
- You are talking in a casual or general way
- You are not sure how to say “genera” out loud — genuses is easier
How to say them: Genera sounds like JEN-uh-ruh. Genuses sounds like JEN-uss-iz.
Easy way to remember: The “a” in genera links to “academic.” Genuses is the friendly, casual cousin.
The Rule in One Line: Use genera in science and formal writing, genuses in everyday English.
Real-Life Examples With Genera and Genuses
- Our biology teacher taught us about ten new plant genera this week. (school science)
- I saw two different bird genuses in the park today. (everyday talk)
- The museum has fossils from over 200 extinct genera. (formal writing)
- My daughter asked me how many genuses of dinosaurs there were. (casual conversation)
- Scientists put lions, tigers, and leopards in the same genus, called Panthera. (singular — just one group)
You are doing great. Now let us look at the mistakes many learners make.
The Most Common Mistakes With the Plural of Genus
Even native English speakers get confused by this word — so if you have ever felt unsure, you are not alone.
Mistake 1: Using “genus” for more than one
✗ Scientists have found many new genus this year.
✓ Scientists have found many new genera this year.
How to remember: One genus, many genera. The plural always needs a different ending — never leave it as genus.
Mistake 2: Writing “geni” or “genii” instead of “genera”
✗ The book lists over 50 geni of insects.
✓ The book lists over 50 genera of insects.
How to remember: Genus does NOT follow the cactus / fungus rule. It does not become “geni.” It becomes genera — with an -era ending.
Mistake 3: Using “genera” for just one group
✗ Lions belong to the genera Panthera.
✓ Lions belong to the genus Panthera.
How to remember: Genera always means more than one. For just one group, always say genus.
Other Latin words that follow a similar irregular pattern: opus → opera, corpus → corpora. These all take an -era or -ora ending in their formal plural.
Test Yourself: Genera or Genuses?
Choose the correct answer for each sentence. Click Check to see if you are right.
1. The biology textbook describes over 300 plant _______ in this chapter.
2. My little brother asked how many bug _______ live in our garden.
3. Lions and tigers belong to the same _______, called Panthera.
4. I told my friend I love learning about different fish _______ at the zoo.
5. The scientific paper compared 12 extinct _______ of dinosaurs.
Keep Going — You Are Building Something
You just learned the plural of genus. That is one more tricky Latin plural you will never get wrong again.
Genus becomes genera because it comes from Latin. But not every Latin word ending in -us follows the same rule. The word fungus also comes from Latin — but its plural is very different. Do you know if it is funguses or fungi? And which one should you use when?
Next lesson: What’s the Plural of Fungus?
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My name is Khamis Maiouf. I am the creator of the English Teacher Site, dedicated to providing valuable resources and insights for students around the world. With a passion for education and a commitment to helping students enhance their skills, I aim to make English teaching more effective and enjoyable for both educators and students.
