Word Formation
Prefixes, suffixes, and 120+ word family tables — organised A–Z and by topic, with Cambridge Use of English Part 3 practice.
What is word formation?
Building words from roots
Word formation is the system of rules English uses to create new words — by adding prefixes (before the root) or suffixes (after the root). Understanding this system lets you decode unfamiliar words and produce the correct form in context.
121Word families
30+Key prefixes
40+Key suffixes
9Topic groups
Why it matters for Cambridge exams
Use of English Part 3 (Word Formation) gives you a root word in capitals and asks you to change it to fit a gap in a sentence:
The results of the experiment were quite ________. EXPECT
Answer: unexpected — negative prefix un- + adjective form -ed
Answer: unexpected — negative prefix un- + adjective form -ed
You must identify: (1) the required part of speech, (2) the correct suffix, (3) whether a negative prefix is also needed. All three must be correct for the mark.
- B2 First: 8 items — 1 mark each
- C1 Advanced: 8 items — 1 mark each
- C2 Proficiency: 8 items — 1 mark each
The four questions to ask
- What part of speech is needed? — look at the position in the sentence. Before a noun = likely adjective or another noun. After a verb = likely noun or adverb. After to = verb.
- Which suffix creates that part of speech? — nouns: -tion, -ness, -ity, -ment, -ance; adjectives: -ful, -less, -ive, -al, -ous, -able; adverbs: -ly; verbs: -ise, -ify, -en.
- Is a negative prefix needed? — check the sentence meaning. Common negatives: un-, in-, im-, ir-, il-, dis-, mis-.
- Are there spelling changes? — happy → happiness, create → creativity, describe → description, occur → occurrence.
Common traps
- Double transformation: some items need both suffix AND prefix — EMPLOY → unemployment. Always check for both.
- Spelling changes: -tion often changes the stem — describe → description, repeat → repetition.
- -ful vs -less: opposite meanings, identical structure. Read the sentence carefully.
- Irregular forms: strong → strength, long → length, wide → width, high → height.
- -ance/-ence are nouns, not adjectives: important → importance (noun, not an adjective form).
- -ic adjectives take -ally: dramatic → dramatically, basic → basically. Exception: public → publicly.
Prefixes
Before the root
Prefixes change a word's meaning but not its part of speech. The most tested type in Cambridge exams is negative prefixes — choosing the wrong one is a frequent error, since the correct prefix depends on the root, not a predictable rule.
Negative prefixes
un-not / reverse of
- happy→unhappy
- expected→unexpected
- employment→unemployment
- aware→unaware
- pack→unpack
in-not (Latin roots)
- complete→incomplete
- formal→informal
- secure→insecure
- accurate→inaccurate
- direct→indirect
im-not (before m/p/b)
- possible→impossible
- polite→impolite
- patient→impatient
- mature→immature
- moral→immoral
ir-not (before r)
- regular→irregular
- relevant→irrelevant
- responsible→irresponsible
- rational→irrational
- reversible→irreversible
il-not (before l)
- legal→illegal
- logical→illogical
- legible→illegible
- literate→illiterate
- legitimate→illegitimate
dis-not / opposite
- agree→disagree
- honest→dishonest
- appear→disappear
- satisfied→dissatisfied
- organised→disorganised
mis-wrongly / badly
- understand→misunderstand
- lead→mislead
- behave→misbehave
- interpret→misinterpret
- use→misuse
non-not (factual/neutral)
- fiction→non-fiction
- existent→non-existent
- verbal→non-verbal
- renewable→non-renewable
- sense→nonsense
Degree, time and position prefixes
over-too much / above
- work→overwork
- estimate→overestimate
- confident→overconfident
- crowded→overcrowded
under-too little / below
- estimate→underestimate
- rated→underrated
- achieve→underachieve
- funded→underfunded
re-again / back
- use→reuse
- consider→reconsider
- build→rebuild
- assure→reassure
pre-before
- view→preview
- arranged→prearranged
- occupied→preoccupied
- historic→prehistoric
inter-between / among
- national→international
- active→interactive
- connected→interconnected
- dependent→interdependent
self-by / of oneself
- employed→self-employed
- confident→self-confident
- sufficient→self-sufficient
- aware→self-aware
out-surpass / beyond
- number→outnumber
- perform→outperform
- weigh→outweigh
- spoken→outspoken
multi-many
- cultural→multicultural
- national→multinational
- media→multimedia
- tasking→multitasking
Suffixes
After the root
Suffixes change the part of speech. This is the core skill in Cambridge Word Formation — identifying which suffix creates the required part of speech, and applying any spelling changes.
Noun suffixes
-tion / -sionaction / state
- educate→education
- decide→decision
- pollute→pollution
- discuss→discussion
- describe→description
-nessstate / quality of
- happy→happiness
- aware→awareness
- dark→darkness
- lonely→loneliness
- weak→weakness
-ity / -tystate / quality of
- equal→equality
- creative→creativity
- possible→possibility
- loyal→loyalty
- flexible→flexibility
-mentaction / result
- achieve→achievement
- develop→development
- employ→employment
- disappoint→disappointment
- manage→management
-ance / -encestate / quality (noun)
- important→importance
- different→difference
- persist→persistence
- rely→reliance
- tolerate→tolerance
-er / -or / -istperson / agent
- teach→teacher
- direct→director
- science→scientist
- journal→journalist
- economy→economist
Note: -ance / -ence are noun suffixes only. importance = noun. Never write importantance as an adjective.
Adjective suffixes
-fulhaving / full of
- help→helpful
- stress→stressful
- success→successful
- power→powerful
- care→careful
-lesswithout / lacking
- help→helpless
- care→careless
- home→homeless
- harm→harmless
- hope→hopeless
-ive / -ativetending to / having quality
- create→creative
- compete→competitive
- imagine→imaginative
- attract→attractive
- inform→informative
-al / -ialrelating to
- nation→national
- environment→environmental
- finance→financial
- technology→technological
- commerce→commercial
-ous / -ioushaving the quality of
- danger→dangerous
- ambition→ambitious
- mystery→mysterious
- fame→famous
- vary→various
-able / -iblecapable of
- rely→reliable
- accept→acceptable
- sense→sensible
- flex→flexible
- sustain→sustainable
Verb & adverb suffixes
-ise / -izemake / become (verb)
- modern→modernise
- popular→popularise
- global→globalise
- character→characterise
-ify / -fymake / cause (verb)
- simple→simplify
- intense→intensify
- just→justify
- class→classify
-enmake / become (verb)
- wide→widen
- short→shorten
- strength→strengthen
- dark→darken
-lyin a … way (adverb)
- quick→quickly
- significant→significantly
- fortunate→fortunately
- exception→exceptionally
-ic adjectives → -ally: dramatic → dramatically, basic → basically, automatic → automatically. Exception: public → publicly.
Word Families
121 families — A–Z and by topic
Each table shows all major forms with examples. Items marked exam appear frequently in Cambridge Part 3. Search, browse A–Z, or explore by topic.
Use of English Part 3
Word formation practice
Read each sentence and write the correct form of the word in capitals. One mark per item — spelling counts.
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