❖ Unit 8 ❖ International Organisations ❖ Grammar ❖

Prefixes & Suffixes

Prefixes (before a word) and suffixes (after a word) change meaning and word class. Mastering them unlocks hundreds of words from a single root.

Prefixes — making opposites

Common negative prefixes: un-, in-, im-, il-, ir-, dis-, mis-, non-, under-, over-, re-

Prefix	Used before	Examples
un-	most adjectives/verbs	unsafe, unhappy, unlucky, undo
in-	before most consonants	incorrect, invisible, independent
im-	before m, p	impossible, impolite, immoral
il-	before l	illegal, illiterate, illogical
ir-	before r	irresponsible, irregular, irrelevant
dis-	verbs/adjectives	disagree, dislike, disappear
mis-	= wrongly	misunderstand, misuse, mispronounce
over-	= too much	overeat, oversleep, overpay
under-	= too little	underestimate, underdeveloped, undercooked
re-	= again	retype, rewrite, rebuild

Practice — Prefixes (opposites)

Complete the chart

safe → unsafe
responsible → irresponsible
logical → illogical
kind → unkind
satisfied → dissatisfied
patient → impatient
legal → illegal
pleasant → unpleasant
important → unimportant
polite → impolite
literate → illiterate
lucky → unlucky
dependent → independent

Practice — Prefixes in sentences

Add the appropriate prefix

The teacher corrects his students when they (pronounce) mispronounce a word.
I have to (type) retype all the essay.
Most people (sleep) oversleep on Sundays.
Our association organised an (smoking) anti-smoking campaign last week.
African countries are still (developed) underdeveloped.
The advantages of the internet (number) outnumber its disadvantages.
They refused to give him a job because he is (qualified) unqualified.
Many teenagers are (responsible) irresponsible.
Morocco and Europe are combating (legal) illegal emigration.

Suffixes — changing word class

Noun-forming suffixes

-tion / -ation / -sion: prevent → prevention, describe → description, decide → decision
-ment: involve → involvement, manage → management, achieve → achievement
-ity: responsible → responsibility, generous → generosity, equal → equality
-ness: happy → happiness, sad → sadness, kind → kindness
-ence / -ance: absent → absence, important → importance, confident → confidence
-ism: terror → terrorism, capital → capitalism, optimist → optimism
-acy: literate → literacy, accurate → accuracy, private → privacy
-y / -ery: discover → discovery, brave → bravery

Adjective-forming suffixes

-ful: success → successful, harm → harmful, beauty → beautiful
-less: harm → harmless, home → homeless, hope → hopeless
-al: nature → natural, finance → financial, technology → technological
-ous: courage → courageous, danger → dangerous, fame → famous
-ic: enthusiasm → enthusiastic, magnet → magnetic, history → historic
-y: wealth → wealthy, noise → noisy, sleep → sleepy
-able / -ible: comfort → comfortable, response → responsible
-ive: imagination → imaginative, cooperation → cooperative, create → creative
-ed / -ing: bore → bored / boring; disappoint → disappointed / disappointing

Practice — Verb/Adjective → Noun

Complete the chart

involve → involvement
manage → management
prevent → prevention
describe → description
generous → generosity
responsible → responsibility
hospitable → hospitality
pessimistic → pessimism
enthusiastic → enthusiasm
absent → absence
self-confident → self-confidence
wise → wisdom
happy → happiness
sad → sadness
accurate → accuracy
illiterate → illiteracy

Practice — Noun → Adjective

Complete the chart

success → successful
harm → harmful / harmless
nature → natural
finance → financial
wealth → wealthy
technology → technological
ecology → ecological
tourism → touristic
enthusiasm → enthusiastic
hazard → hazardous
courage → courageous
imagination → imaginative
cooperation → cooperative
talent → talented
comfort → comfortable

Practice — Add suffixes in sentences

Correct form

Gad Elmaleh has a great (art) artistic talent.
(Unemploy) Unemployment is the most serious problem in today's world.
Due to the (finance) financial crisis, many companies went bankrupt.
Students find it difficult to (memory) memorise philosophy and history lessons.
The Moroccans are known for their (generous) generosity and kindness.
"Do you play any (music) musical instrument?" my friend asked.
Lynda couldn't make any (decide) decision about her marriage.
Baity is an NGO that takes care of (home) homeless children.
Immigrants usually suffer from (discriminate) discrimination in host countries.
My friends made me an (forget) unforgettable surprise on my birthday.

❖ Key Takeaways ❖

① Prefixes negate

Most prefixes (un-, in-, dis-, im-, il-, ir-) make the opposite. Pay attention to the first letter of the word: l → il-, m/p → im-, r → ir-.

② Suffixes change class

-tion / -ment / -ity / -ness → noun. -ful / -less / -al / -ous / -ic → adjective. -ly → adverb.

③ Family trees

One root → many words. Example: responsibility (noun) / responsible (adj) / responsibly (adv) / irresponsible (opposite).

❖ Exam tip

The "word formation" exercise is worth 4-5 points per exam. Always read the surrounding sentence to find out the word class needed (noun? adjective? verb?). Tip: a noun usually follows "the/a/an", an adjective follows "is/seems/looks".