What does the prefix mono- mean?
Mono- comes from the Greek monos, which means "alone" or "single". It shows that there is only one element or one category. The central idea is always "one and only one".
ESEN
Prefix · one / single
mono-
Signals one or uniqueness: monologue, monopoly, monotone, monochrome, monolingual.
Scientific
Written by Bryan López, English teacher · Updated
Mono- in science and language
Mono- is very productive in the sciences, where it names things made of one single element or with a single characteristic, like one color or one species. In linguistics, it also describes someone who speaks one language: the opposite of bilingual or multilingual. If you see mono- in a word, look for the hidden "one".
How it is used
Attaches to nouns and adjectives:
- mono- + nounlogue → monologuepoly → monopolyrail → monorailchrome → monochromelingual → monolingual
- mono- + element/compoundoxide → monoxidesyllable → monosyllableculture → monoculturetheism → monotheism
Pronunciation: /ˈmɒnəʊ/ in British English, /ˈmɑːnoʊ/ in American English.
How it is pronounced
mono-/ˈmɒnəʊ/
Tap the button to hear how the prefix sounds. Each word in the table has its own audio.
Examples
Root word
With mono-
In a phrase
- loguemonologueThe actor improvised a ten-minute monologue entirely from memory.
- polymonopolyThe government broke up the company's monopoly on the market.
- tonemonotoneHe spoke in a flat monotone that made everyone sleepy.
- chromemonochromeThe photographer printed the portrait in monochrome for a timeless feel.
- lingualmonolingualGrowing up monolingual made learning a second language harder.
- oxidemonoxideCarbon monoxide is colourless and odourless, making it very dangerous.
- railmonorailThe airport monorail connects the terminals quickly and smoothly.
Common mistakes
monotonous = only about a single musical note
monotonous = lacking variety and therefore boring, applied to sounds, tasks, or anything repetitive
"Monotonous" describes anything repetitive and dull: a monotonous job (no variety), a monotonous voice (no expression), a monotonous landscape. It is not limited to music.
carbon monoxide = carbon dioxide (CO₂)
carbon monoxide = CO (one oxygen atom); carbon dioxide = CO₂ (two oxygen atoms)
Mono- = one oxygen: carbon monoxide (CO) is the odourless, toxic gas. Di- = two oxygens: carbon dioxide (CO₂) is the gas exhaled by humans and absorbed by plants.
A trick to remember it
Picture a monocle, a single lens for a single eye: mono- = one, unique. monologue, monopoly.
Practise what you learned
Exercise 1 · Form the word
Exercise 2 · Pick the right one
"Carbon ___ is an odourless, colourless gas that is extremely dangerous in enclosed spaces."
Exercise 3 · Pick the right one
What is the difference between "monolingual" and "bilingual"?
Frequently asked questions
What does the prefix mono- mean in English?
The prefix mono- signals one or uniqueness: monologue, monopoly, monotone, monochrome, monolingual.
How do you pronounce mono-?
The prefix mono- is pronounced /ˈmɒnəʊ/. For example, "monologue".
Can you give an example of a word with mono-?
"logue" becomes "monologue". It is a typical example of the mono- prefix.
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