Prefixes in English Grammar : Definition, Examples & How to use them?

In the English language, there are times when we come across a one-syllable or a group of letters being added to a base word to alter its meaning. For example, let us then consider the word “possible”. Adding the letters “im-” before it creates a new word called impossible which means the opposite of possible.

Such types of syllables or groups of letters (im-) are called prefixes and they play a key role in English grammar. Knowledge of prefixes helps enhance vocabulary and comprehension.

What is a Prefix in English?

A prefix is a group of letters (sometimes a single letter) that is added at the start of a base word to alter its meaning. These letters are affixes. Affixes do not have any significance or meaning when used independently. They are either added before or afterward to create new words with new meanings. When affixes are added before a word, they are called prefixes and when they are added after a word, they are known as suffixes.
Example of a prefix: Use of the letters “hemi-” before the word ”sphere” to create a new word hemisphere which means half of a sphere.

Definitions of a Prefix

A prefix is “an affix attached to the beginning of a word, base, or phrase and serving to produce a derivative word or an inflectional form,” according to the Merriam-Webster Dictionary. According to the Collins Dictionary, a prefix is a letter or set of letters that are added to the beginning of a word to make a separate word, such as “un-” or “multi-.”

List of 35 Most Common Prefixes in English

Here are some of the most common prefixes list in English with their meanings and examples. 

Prefix	Meaning	Examples
Ambi-	Both and around	Ambidextrous, ambivalence, ambiguous, ambidexterity
Co-	Together	Coexist, correlation, colleague, co-worker
Anti-	Against	Anti-national, antibiotic, antibody, antisocial
Mono-	One	Monogamy, monotonous, monolingual, monologue
Semi-	Half	Semifinal, semicircle, semiautomatic, semiconscious
Sub-	Below	Subconscious, subtropical, submerge, subordinate
Un-	Opposite or not	Unacceptable, unabashed, unlike, unfair
Uni-	One	Universe, unilateral, unicycle, uniform
Under-	Not enough	Underage, underperform, undervalue, underrate
In-	Opposite or not	Insufficient, insane, independent, invalid
Bi-	Two	Bilingual, bicycle, biweekly, bilateral
Homo-	Same	Homogeneous, homogeny, homosexual, homonym
Contra-	Against or opposite	Contradict, contraceptive, contrary, contradictory
Dis-	Opposite or not	Dislike, disintegrate, dishonour, disappear
Em-	To make or put into	Empathy, empirical, emphasis, embankment
Hetero-	Different	Heterosexual, heterogeneous, heterogamous, heteronomous
Hind-	After or back	Hindsight, hindlimb, hindwing, hindquarters
Im-	Opposite or not	Immoral, impatient, impartial, imperfect
Inter-	Between	Interstate, international, intermediate, interaction
Mis-	Wrong	Miscommunication, miscalculate, misconception, misfortune
Trans-	Across or changed	Transform, translate, translucent, transgender
Tri-	Three	Triangle, tripod, trilingual, triathlon
Non-	Without	Nonsense, non-alcoholic, nonstop, non-fiction
On-	Near or connected	Onset, online, ongoing, onlooker
Pan-	All	Pandemic, pan-Indian, pansexual, pancreatic
Ped-	Foot	Pedicure, pedestrian, pedal, pedometer
Post-	After	Postpone, postseason, postgraduate, postnatal
Pre-	Before	Prepone, precaution, prejudice, premeditated
Pro-	Forward or for	Progress, product, promise, procrastinate
Re-	Again	Research, repeat, rework, recycle
Sur-	Over	Surface, surcharge, surplus, surpass
Twi-	Two	Twin, twice, twi-headed
Ultra-	Beyond	Ultra-conservative, ultraviolet, ultrasound, ultrasonic
Extra-	More than	Extraterrestrial, extra-curricular, extramarital, extraordinary
Up-	Higher or better	Uphill, upgrade, update, upturned

When to Use Prefixes?

Prefixes can be used for multiple purposes. One of the common uses of prefixes is to mean the opposite or negative of the base word. For example, using the prefix “un-” before necessary to create the word unnecessarily or using “dis-” before approving to form disapprove. Both the new words unnecessary and disapprove are the opposites of their base words respectively.

Prefixes are also used to reduce a sentence or a phrase to a single word without changing it. For example, instead of saying “He is showing way too much confidence than required”, we can simply say “He is overconfident”.

How to use prefixes

It is important to understand the way prefixes are used. It should be noted that while adding a prefix to a base word, there should not be a change in the spelling of either the base word or the prefix. For example: unkind (a combination of “un-” and “kind”). Even if it leads to double consonants, the same rule should be followed. Example: coordinate, irresponsible.

Certain rules need to be followed while using hyphens to join prefixes with words. This will be discussed in the next section.

Prefixes Examples

Some of the most common examples of Prefixes are:
1. Unpopular
2. Bicycle
3. Misunderstanding
4. Prepone
5. Online
6. Underage
7. Coexist
8. Pandemic
9. Independent
10. Extraordinary

Writing Prefixes With Hyphens

Use of hyphens in prefixes can be confusing as some prefixes use hyphens while some don’t. Also, there are certain prefixes which may or may not use prefixes based on their meanings. Let is take the case of the prefix “ex-“. There are two meanings of this prefix- “belonging to the past” and “out of/from”. When it means belonging to the past, hyphens are used (ex-husband, ex-president). When it means “out of/ from”, then hyphens are not required (exterritorial, exstipulate)

Hyphens are used when prefixes are added to proper nouns. Example: pro-Nazi, un-Indian, trans-Pacific.

Hyphens are required when the prefix ends with a vowel and the base word starts with the same vowel. Common examples include re-enter, semi-industrious, semi-independent. However, English is a language of exceptions and for some cases, if the vowel is “o” for both the prefix and the word, then the hyphen is not required. For example: coordinate, cooperate.

When the prefix ends with a vowel and the base word starts with a different vowel, hyphens are not required. For example: hydroelectricity, proactive, reactivate.

How to Learn Prefixes in English?

Prefixes are hidden in thousands of words and it is important to learn them to improve vocabulary skills. One of the best ways to learn prefixes is by creating a list of the most popular prefixes and studying them. Try to understand how they are used in a sentence to know them better.

Taking online tests, quizzes can also go a long way to help you get accustomed to prefixes. Sources of visual entertainments like movies, videos, tv series can also aid you to learn prefixes. Keep the subtitles on if it is difficult to understand and interpret the audio.

Prefixes Exercises

1. Put words in the blanks as per required.

Que. She was ________. She started crying. (happy)
A. Unhappy

Que. I think you should ________ the decision. The move will have big consequences. (consider)
A. Reconsider

Que. Even though she is young, she is quite ________ (dependent)
A. Independent

Que. All these quarrels have made him ________ among his peers. (popular)
A. Unpopular

2. Write prefixes that mean the Opposite of the following words-

a) Agree- disagree
b) Correct- incorrect
c) Fold- unfold
d) Spell- misspell
e) Behave- misbehave
f) Connect- disconnect
g) Understand- misunderstand

Prefixes- FAQs

Que 1. What is Prefix?

Prefix is a group of letters (sometimes a single letter) which is added at the start of a base word to alter its meaning.
Example of a prefix: Use of the letters “hemi-” before the word ”sphere” to create a new word hemisphere which means half of a sphere.

Que 2. How do Prefixes work?

Prefixes work by getting added to a base word and changing the meaning of it. They are an integral part of the English language. They are always added before a word. Examples: 
1. Please “postpone” the meeting.
2. The animals and birds “coexist” in an ecosystem.
3. She is “riding” a bicycle.

Que 3. How to use a Prefix?

It is important to understand the way prefixes are used. It should be noted that while adding a prefix to a base word, there should not be a change in the spelling of either the base word or the prefix. For example: unkind (combination of “un-” and “kind”). Even if it leads to double consonants, the same rule should be followed. Example: coordinate, irresponsible.

There are also certain rules that need to be followed while using hyphen to join prefixes with words. Hyphens are used when prefixes are added to proper nouns. Example: pro-Nazi, un-Indian, trans-Pacific.

Hyphens are required when the prefix ends with a vowel and the base word starts with the same vowel. Common examples include re-enter, semi-industrious, semi-independent. However, English is a language of exceptions and for some cases, if the vowel is “o” for both the prefix and the word, then the hyphen is not required. For example: coordinate, cooperate.

When the prefix ends with a vowel and the base word starts with a different vowel, hyphens are not required. For example: hydroelectricity, proactive, reactivate.

Que 4. How can we learn Prefixes?

One of the best ways to learn prefixes is by creating a list of the most popular prefixes and studying them. 
Taking online tests, quizzes can also go a long way to help you get accustomed to prefixes. Sources of visual entertainments like movies, videos, tv series can also aid you to learn prefixes. Keep the subtitles on if it is difficult to understand and interpret the audio.

Que 5. What are the advantages of using Prefix?

Prefixes have the following advantages:

1. It can shorten a phrase into a single word. For example, instead of saying “He is showing way too much confidence than required”, we can simply say “He is overconfident”.
2. They can be used to mean the opposite of any word. Example: use- misuse, correct- incorrect.