What’s the plural of “volcano”?
The plural of volcano is volcanoes or volcanos; both are accepted plurals to mention more than one volcano. As a general pattern, many singular nouns that end in –o add –s or –es as a plural noun. Other examples are tomato/tomatoes, potato/potatoes, heroes, echoes, etc.
We visited several active volcanoes on the island.
The farmer harvested many juicy potatoes this year.
The kids loved dressing up as heros for the party.
I watched many old videoes on streaming services.
This is not invariably the case, since sometimes nouns that end in ‘o’ just add an –s as a plural noun, like with radio/radios and video/videos. For the most part, the –es is preferred as the standard plural form, and more common for singular nouns ending in o.
What are volcanoes?
According to USGS.gov, volcanoes are “openings, or vents where lava, tephra (small rocks), and steam erupt onto the Earth’s surface.”
Nouns that end in “-o” / “-es” or “-s”
| singular nouns ending in “-o” | plural “-es” / “-s” |
| tomato | tomatoes |
| buffalo | buffaloes or buffalos |
| potato | potatoes |
| hero | heroes |
| volcano | volcanos or volcanoes |
The plural of “volcano,” associate it with other -o words that add -es, like “potato” and “tomato,” creating a mental group of “-oes” plurals.
“Volcano”, used in sentences
The following sentences show the correct use of the word volcano in context. Sentence examples are from USGS on volcanoes:
1. Cinder cones are the simplest type of volcano.
2. Pieces of the volcano collapse as rock falls or as landslides.
3. This connection to fresh magma allows the volcano to erupt over and over again in the same location
4. Kīlauea volcano on the Island of Hawai‘i is one of the most active volcanoes on Earth.
5. Ojos del Salado in Chile is the tallest composite volcano on Earth with a summit elevation (height above sea level) of 22,615 feet;
Examples of the word volcanos/volcanoes used in sentences
The following sentences show the correct use of the word volcanos/volcanoes in context. Sentence examples are from USGS on volcanoes:
1. There are about 1,350 potentially active volcanoes worldwide, not counting the volcanoes under the oceans.
2. Kīlauea volcano on the Island of Hawai‘i is one of the most active volcanoes on Earth.
3. USGS scientists monitor over 160 active and potentially active volcanoes in the United States.
4. Most of these volcanoes are located in Alaska, a state where eruptions occur almost every year.
5. The rest of the volcanoes are located throughout the American West, and in Hawaii (see our volcano activity map for their locations).
Origin of the word volcano
From etymology online on volcano (n.):
1610s, from Italian vulcano “burning mountain,” from Latin Vulcanus “Vulcan,” Roman god of fire, also “fire, flames, volcano”.
What’s the difference between they’re, their, and there?
Sources
Work Sheet
According to the blog post, what are the accepted plural forms of “volcano”?
Which plural form of “volcano” is mentioned in the post as being generally preferred and more common?
For singular nouns ending in “-o”, the post states that adding -s or -es is a general pattern. Which ending is mentioned as generally more common for plurals?
Which of the following nouns ending in “-o” is listed in the post as an example that typically adds only “-s” for its plural?
According to the usage note in the post, which is the correct plural form for “hero”?
We visited several active on the island.
The farmer harvested many juicy this year.
The kids loved dressing up as for the party.
I watched many old on streaming services.
There are about 1,350 potentially active worldwide.
Frequently Asked Questions
What’s the plural of volcano?
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Are ‘volcanoes’ and ‘volcanos’ both correct?
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Is one plural form preferred for volcano?
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How do -o nouns usually form plurals?
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Are there common mistakes with -o plurals?
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Yash, D. "What’s the Plural of Volcano?." Grammarflex, Jun 19, 2025, https://www.grammarflex.com/whats-the-plural-of-volcano/.
