A prefix is a letter or a group of letters that appears at the beginning of a word and changes the word’s original meaning. It is important to know what different prefixes mean as they can help you to understand the additional meanings of words or unknown English words you come across.
Nouns, like adjectives or verbs, can be formed using prefixes. For example, the prefix non- can mean ‘not’ or ‘opposite.’ Adding non- to the word ‘sense’ gives you the word ‘nonsense’, which means words that have no meaning.
- She lives in a subdivision outside of a large city.
- That is a bunch of nonsense. I can’t believe you think that.
- He has to talk to his ex-wife frequently because of the children.
- The level of malnutrition in the children of this town is astonishing.
- There was a lot of unrest among the people after the president was arrested.
- For children with parents from different countries, biculturalism and bilingualism are often parts of their lives.
- Her learning disability has made it difficult for her to keep up with classmates.
Prefix meanings
Prefixes are added to the root (base word) and may have various meanings.
To counter the meaning of a word
Prefixes like anti-, de-, dis-, un- or non– are used to mean opposite of a word:
- body – antibody
- sense – nonsense
To increase/decrease strength of a word
Prefixes over-, under-, up-, down-, and hyper- denote the degree, quality, quantity, or a trend:
- activity – hyperactivity
- fall – downfall
To quantify something
Prefixes like mono-, bi-, uni-, di-, and omni- indicate the quantity of something in a word:
- sulfide – disulfide
- bus – omnibus
To denote the degree of something
Prefixes mega-, mini-, macro, and micro- express the degree of something in a word:
- skirt – miniskirt
- economics – macroeconomics
Tips to learn noun prefixes
Here are a few things to remember when learning prefixes:
- Different prefixes in English can have similar meanings, such as un-, in- and non- all of which mean ‘not’ or ‘opposite of.’ Also, the prefixes mis- and ir- mean ‘wrong,’ ‘wrongly,’ or ‘incorrectly.’
- Notice that double letters are possible. For example, when you add the prefix im- to words that begin with the letter ‘m,’ you get two ‘m’s as in ‘immeasurability.’ The same is true for many other prefixes.
- When adding a prefix to a word, the spelling of the base word never changes. For example, the prefix un- did not change the spelling of the word ‘happiness.’
- Watch out for ‘lookalikes’ – words that look like they contain prefixes but, in fact, do not. For example, the un- in the word “uncle” is not a prefix, nor is the re- in ‘real.’
List of common noun prefixes
Here’s a list of common prefixes common noun prefixes and their meaning:
| Prefix | Meaning | Examples |
| anti- | against | antibody, antifreeze |
| bi- | referring to two | bicycle, bilingualism, biculturalism |
| co- | together, with | coordination, cooperation |
| semi- | half of, not complete | semicircle, semidesert, semidarkness |
| mal- | bad, not enough | malfunction, malnutrition, maltreatment |
| ex- | former | exwife, ex-president, ex-smoker |
| sub- | under, below | subdivision, submarine, subset |
| dis- | bad, opposite of | disability, disbelief, discomfort |
| non- | opposite of | nonsense, nonfiction |
| un- | lack of | unfairness, unrest, unemployment |
| over- | excessive, above | overwork, overheating |
| Note: You may see some nouns with prefixes written with a hyphen (-). This happens when a verb is not commonly used with a prefix, such as: ex-president. This will also depend on the type of English (American or British). |
Here’s a useful video from EngVid demonstrating different prefixes in use:
Read more on this topic:
Noun Formation: Common Suffixes