Prefixes and Suffixes in English

Prefixes and suffixes are groups of letters added to words to change their meaning, form, or grammatical function.

A prefix is added to the beginning of a word:

un + happy → unhappy

A suffix is added to the end of a word:

happy + ness → happiness

Prefixes and suffixes are both types of affixes. Learning them can help you understand unfamiliar words, recognize word classes, and form new words correctly.

What Are Prefixes and Suffixes?

A prefix is a letter or group of letters added to the beginning of a base word or stem to form a new word or change its meaning.

Examples:

• happy → unhappy
• write → rewrite
• understand → misunderstand
• possible → impossible

A suffix is a letter or group of letters added to the end of a base or stem.

Examples:

• happy → happiness
• teach → teacher
• care → careful
• quick → quickly

The word or form to which an affix is added is called a base.

For example:

un + help + ful

• un- = prefix
• help = base
• -ful = suffix

A word can have a prefix, a suffix, or both.

Prefix vs. Suffix: What Is the Difference?

The main difference between a prefix and a suffix is their position and function.

Prefixes commonly change the meaning of a word:

• happy → unhappy
• write → rewrite
• agree → disagree

Suffixes often form words belonging to particular word classes:

• teach → teacher
• happy → happiness
• care → careful
• quick → quickly

However, these are general patterns rather than absolute rules. Not every suffix changes word class, and the effect of an affix depends on the particular word.

Common Prefixes in English

Here are some common English prefixes and their meanings:

The meaning of a prefixed word is often related to the meaning of the prefix, but learners should still learn words in context because meanings are not always completely predictable.

Prefixes by Meaning

Prefixes can be grouped according to the kinds of meanings they commonly express. These are useful meaning-based groups, not rigid grammatical types.

Negative and Opposite Prefixes

Several prefixes can create negative or opposite meanings.

un-

• happy → unhappy
• fair → unfair
• certain → uncertain

dis-

• agree → disagree
• honest → dishonest
• connect → disconnect

in-

• correct → incorrect
• active → inactive

The negative prefix in- has related forms im-, il-, and ir- depending on the beginning of the base word:

• possible → impossible
• legal → illegal
• regular → irregular

non- also expresses absence or negation:

• non-fiction
• non-smoking
• non-payment

These prefixes are not freely interchangeable. English uses established combinations, so forms such as impossible and irregular should be learned as words rather than created by guessing.

Prefixes of Time and Repetition

Some prefixes express time, sequence, or repetition.

pre- means before:

• prehistoric
• prewar
• prepay

post- means after:

• postwar
• postgraduate
• post-election

re- commonly means again:

• rewrite
• rebuild
• reconsider

For example:

She rewrote the report.

Here, re- indicates that the action of writing was performed again.

Prefixes of Degree and Amount

Some prefixes indicate degree, amount, or extent.

over- can mean too much or excessively:

• overcook
• overwork
• overcharge

under- can mean too little, insufficiently, or below:

• undercook
• underestimate
• underpay

super- can express something above, beyond, or unusually great:

• superhuman
• superstar

The exact meaning depends on the word in which the prefix occurs.

Prefixes of Position and Relationship

Some prefixes express position, movement, or relationships between things.

inter- commonly means between or among:

• international
• interact
• interconnect

sub- commonly means under or below:

• submarine
• substandard

trans- can mean across or beyond:

• transatlantic
• transnational

These prefixes are especially common in academic, technical, and formal vocabulary.

Common Suffixes in English

Suffixes are especially useful in word formation because many of them are associated with particular word classes.

For example:

teach → teacher
verb → noun

care → careful
noun → adjective

modern → modernize
adjective → verb

quick → quickly
adjective → adverb

A suffix can often provide a clue about whether a word is a noun, adjective, verb, or adverb, although there are exceptions.

Noun Suffixes

Common noun-forming suffixes include:

Examples:

teach → teacher

happy → happiness

develop → development

decide → decision

These suffixes can form nouns referring to people, actions, processes, results, states, qualities, relationships, and other concepts.

Adjective Suffixes

Common adjective-forming suffixes include:

Examples:

help → helpful

danger → dangerous

care → careless

create → creative

These suffixes commonly form words that describe people, things, states, or qualities.

Verb Suffixes

Some suffixes are commonly used to form verbs.

Examples:

wide → widen

simple → simplify

modern → modernize

The spelling -ize is common in American English, while both -ise and -ize occur in British English depending on style and word.

Adverb Suffixes

The most common adverb-forming suffix is -ly.

• quick → quickly
• careful → carefully
• slow → slowly
• happy → happily

Other adverbial endings include -ward(s) and -wise:

• homeward
• backwards
• clockwise

However, an ending does not guarantee a particular word class. For example, friendly and lovely end in -ly but are normally adjectives.

How Prefixes and Suffixes Change Words

Prefixes and suffixes can affect words in different ways.

Prefixes commonly change meaning:

• happy → unhappy
• write → rewrite
• understand → misunderstand
• agree → disagree

In these examples, the prefixed word remains closely related to the meaning of the base, but the prefix changes that meaning.

Suffixes often form a different word class:

• teach → teacher
  verb → noun
• happy → happiness
  adjective → noun
• care → careful
  noun → adjective
• quick → quickly
  adjective → adverb
• strength → strengthen
  noun → verb

This is one reason suffixes can help learners recognize word classes.

However, the relationship is not completely predictable. A suffix may have different effects in different words, and not every word ending in the same letters necessarily contains the same suffix.

Words with Both Prefixes and Suffixes

A word can contain both a prefix and a suffix.

Consider:

unhappiness

un + happy + ness

• un- = prefix
• happy = base
• -ness = suffix

Other examples include:

disagreement

dis + agree + ment

unemployment

un + employ + ment

misunderstanding

mis + understand + ing

Prefixes and suffixes can therefore work together in the same word.

Compare:

happy → unhappy → unhappiness

The prefix un- changes the meaning of happy, while the suffix -ness forms a noun.

Spelling Rules for Prefixes and Suffixes

Adding an affix can affect spelling, especially when a suffix is added. English spelling patterns are useful, but exceptions also occur.

Spelling Rules for Prefixes

Adding a prefix normally does not require changing the spelling of the base.

• un + happy → unhappy
• dis + agree → disagree
• mis + spell → misspell
• over + cook → overcook

Sometimes this creates double letters:

• un + natural → unnatural
• mis + spell → misspell

Do not remove one of the letters simply because two identical letters meet.

The negative prefix in- changes form before certain sounds:

• in- + legal → illegal
• in- + possible → impossible
• in- + regular → irregular

These forms are commonly written il-, im-, and ir-.

Some prefixed words are written with a hyphen, while others are written as one word:

• non-smoking
• post-war
• rewrite
• unhappy

Hyphenation is not completely predictable, so a reliable dictionary should be checked when necessary.

Spelling Rules for Suffixes

Adding a suffix can change the spelling of the base.

Final -y can change to -i:

• happy + -ness → happiness
• easy + -ly → easily
• heavy + -ness → heaviness

A final -e may be dropped before some suffixes:

• create + -ion → creation
• fame + -ous → famous

But the final e is not always dropped:

• hope + -ful → hopeful

A final consonant may be doubled in some formations:

• begin + -er → beginner

Other suffixes can produce less straightforward spelling changes:

• permit → permission
• possible → possibility
• decide → decision

Because suffix spelling is not always predictable, learners should learn common derived words as part of their word families.

Commonly Confused Prefixes and Suffixes

Some affixes have similar meanings or functions but are not interchangeable.

un- and dis-

Both can express negative or opposite meanings:

• happy → unhappy
• agree → disagree
• honest → dishonest

We cannot simply choose either prefix:

• unhappy ✓
• dishappy ✗
• disagree ✓
• unagree ✗

The correct form depends on the established word.

in-, im-, il- and ir-

These are related forms of the negative prefix in-.

• inactive
• impossible
• illegal
• irregular

Their form is influenced by the sound at the beginning of the base.

-ful and -less

These suffixes can sometimes express contrasting meanings:

• helpful / helpless
• useful / useless
• careful / careless

-ful commonly means having or showing something, while -less commonly means without or lacking something.

However, not every word naturally forms both versions.

-er and -ee

These suffixes can sometimes distinguish different participants in an action:

• employer / employee
• trainer / trainee

-er often refers to someone who performs an action, while -ee can refer to someone who receives or experiences it.

This is a useful pattern, but it is not a universal rule for every word.

-tion, -sion and -ssion

These endings commonly occur in nouns:

• educate → education
• decide → decision
• permit → permission
• discuss → discussion

Their spelling depends largely on the established form of the word. There is no single simple rule that predicts the correct ending in every case.

Common Mistakes with Prefixes and Suffixes

Mistake 1: Using the wrong negative prefix

Incorrect:

unpossible ✗

Correct:

impossible ✓

Incorrect:

inregular ✗

Correct:

irregular ✓

Mistake 2: Assuming similar prefixes are interchangeable

Incorrect:

unagree ✗

Correct:

disagree ✓

English uses particular prefixes with particular bases.

Mistake 3: Ignoring spelling changes when adding suffixes

Incorrect:

happyness ✗

Correct:

happiness ✓

Incorrect:

possibleity ✗

Correct:

possibility ✓

Mistake 4: Assuming every ending identifies the word class

The suffix -ly commonly forms adverbs:

quick → quickly

But words such as friendly, lovely, and lonely are adjectives.

A suffix can be a useful clue, but the complete word and its use in the sentence must also be considered.

Mistake 5: Creating words by attaching any suitable-looking affix

Not every base combines naturally with every prefix or suffix.

For example:

develop → development ✓

develop → develoption ✗

Affix patterns can help, but established word forms must still be learned.

Prefixes and Suffixes Exercises with Answers

A. Add a suitable prefix to form a new word.

1. ___happy
2. ___possible
3. ___write
4. ___agree
5. ___understand

B. Add a suitable suffix to form the word shown in brackets.

6. happy → ________ (noun)
7. teach → ________ (person)
8. care → ________ (adjective meaning “showing care”)
9. quick → ________ (adverb)
10. simple → ________ (verb)

C. Identify the prefix, base, and suffix where present.

11. unhappiness
12. disagreement
13. teacher
14. rewrite
15. unemployment

D. Choose the correct word.

16. impossible / unpossible
17. irregular / inregular
18. happiness / happyness
19. disagree / unagree
20. development / develoption

Answers

1. unhappy
2. impossible
3. rewrite
4. disagree
5. misunderstand
6. happiness
7. teacher
8. careful
9. quickly
10. simplify
11. un- + happy + -ness
12. dis- + agree + -ment
13. teach + -er
14. re- + write
15. un- + employ + -ment
16. impossible
17. irregular
18. happiness
19. disagree
20. development

FAQs About Prefixes and Suffixes

What is a prefix?

A prefix is a letter or group of letters added to the beginning of a base or stem to form a new word or change its meaning. For example, adding un- to happy forms unhappy.

What is a suffix?

A suffix is a letter or group of letters added to the end of a base or stem. For example, adding -ness to happy forms happiness.

What is the difference between a prefix and a suffix?

A prefix comes before the base, while a suffix comes after it.

• un + happy → unhappy
• happy + ness → happiness

What are some common prefixes in English?

Common prefixes include un-, dis-, in-, im-, il-, ir-, re-, mis-, pre-, post-, non-, over-, under-, inter-, sub-, and super-.

What are some common suffixes in English?

Common suffixes include -ness, -ment, -tion, -er, -ful, -less, -able, -ous, -ize/-ise, -ify, and -ly.

Do prefixes change the meaning of words?

Yes. Prefixes commonly modify the meaning of the base. For example, re- can mean “again” in rewrite, while un- creates a negative meaning in unhappy.

Do suffixes change the word class?

Suffixes often form words of a different word class, but not always. For example, happy is an adjective and happiness is a noun, while quick is an adjective and quickly is an adverb.