Module 2 - Chapter 12

Word Formation

Master prefixes, suffixes, and root words to build your vocabulary rapidly.

Introduction

Building Words Like Building Blocks

Imagine you have a set of building blocks. Each block is a small piece — a root, a prefix, or a suffix. By snapping different blocks together, you can build hundreds of new words. The root "help" becomes helpful, helpless, unhelpful, helpfulness, helper — five words from one root!

English borrows roots from Latin, Greek, French, and Germanic languages. Understanding how words are assembled means you can decode unfamiliar words on sight and express ideas with precision. Instead of memorising thousands of words one by one, you learn a handful of parts and combine them.

The Three Building Blocks of English Words

Prefix — a letter group added before the root to change its meaning (e.g., un- + happy = unhappy)
Root / Base Word — the core part that carries the main meaning (e.g., happy, write, port)
Suffix — a letter group added after the root to change its meaning or part of speech (e.g., happi- + ness = happiness)

Why does word formation matter for exams and everyday English? (Click to learn) ▼

Formula to Remember

Prefix + Root + Suffix = New Word
un + believe + able = unbelievable
dis + agree + ment = disagreement
re + construct + ion = reconstruction

Common Prefixes

A prefix is attached to the beginning of a word and modifies its meaning. Prefixes never change the part of speech — they only shift the meaning. Learning these 12 prefixes unlocks hundreds of words.

Negative & Reversing Prefixes

Prefix	Meaning	Examples
un-	not, opposite of	unhappy, unusual, unlock, uncertain, unfair
dis-	not, opposite of, remove	disagree, disappear, disconnect, dislike, dishonest
mis-	wrongly, badly	misunderstand, misspell, misuse, mislead, misbehave
anti-	against, opposed to	antisocial, antibacterial, anticlockwise, antivirus

Time, Repetition & Degree Prefixes

Prefix	Meaning	Examples
re-	again, back	rebuild, rewrite, return, review, reconsider
pre-	before	preview, preheat, prehistoric, predict, prepay
over-	too much, above	overwork, overeat, overcome, overlook, overdue
under-	too little, below	underestimate, underpaid, underline, underground

Relationship & Number Prefixes

Prefix	Meaning	Examples
inter-	between, among	international, interact, interview, internet
co-	together, with	cooperate, coexist, co-author, coordinate
sub-	under, below, secondary	submarine, subtitle, subconscious, subdivide
multi-	many	multinational, multimedia, multiply, multilingual

Quick Practice: Add the Correct Prefix

Click each item to reveal the answer.

1. She was _____happy with the result. (opposite of happy) ▼

2. Please _____heat the oven to 180 degrees. (before) ▼

3. He tends to _____eat when he is stressed. (too much) ▼

4. They need to _____write the entire essay. (again) ▼

5. The two countries signed an _____national agreement. (between) ▼

Common Suffixes — Nouns

Unlike prefixes, suffixes change the part of speech of a word. Noun suffixes turn verbs or adjectives into nouns. Mastering these patterns lets you convert any root into its noun form instantly.

-tion / -sion

Meaning: the act or result of

From verb to noun:

create → creation
educate → education
decide → decision
discuss → discussion
inform → information

-ment

Meaning: the result or process of

From verb to noun:

develop → development
agree → agreement
achieve → achievement
manage → management
improve → improvement

-ness

Meaning: the state or quality of

From adjective to noun:

happy → happiness
dark → darkness
kind → kindness
sad → sadness
weak → weakness

-ity

Meaning: the quality or condition of

From adjective to noun:

possible → possibility
creative → creativity
electric → electricity
national → nationality
active → activity

-er / -or

Meaning: a person who does something

From verb to noun (person):

teach → teacher
write → writer
act → actor
direct → director
drive → driver

-ist & -ance / -ence

-ist: a person who practises or believes in

science → scientist
art → artist
piano → pianist

-ance / -ence: a state or quality

important → importance
different → difference
confident → confidence

Spelling Tip: -ness vs -ity

-ness attaches to Germanic/common adjectives and rarely changes the root spelling: kind → kindness, sad → sadness.
-ity attaches to Latinate adjectives and often changes spelling: possible → possibility (drop the -le), creative → creativity (drop the -e).
When in doubt, say it aloud — "sadity" sounds wrong, and "possibleness" sounds awkward. Your ear often knows the right suffix.

Common Suffixes — Adjectives & Adverbs

Adjective suffixes turn nouns or verbs into describing words. Adverb suffixes (mainly -ly) turn adjectives into words that describe how, when, or to what extent something happens.

Adjective-Forming Suffixes

Suffix	Meaning	Examples
-ful	full of, characterised by	beauty → beautiful, care → careful, hope → hopeful
-less	without, lacking	care → careless, hope → hopeless, end → endless
-able / -ible	capable of being	comfort → comfortable, access → accessible, read → readable
-ous	having the quality of	danger → dangerous, fame → famous, nerve → nervous
-ive	tending to, having the nature of	create → creative, act → active, attract → attractive

The Adverb Suffix: -ly

Adding -ly to an adjective creates an adverb that tells us how something is done.

Adjective	Adverb	Example Sentence
quick	quickly	She ran quickly to the bus stop.
careful	carefully	He carefully placed the glass on the table.
beautiful	beautifully	The singer performed beautifully.
happy	happily	They lived happily ever after.

-ful vs -less: Perfect Opposites

Think of -ful and -less as a light switch. One turns the quality ON, the other turns it OFF:

careful (full of care) vs. careless (without care)
hopeful (full of hope) vs. hopeless (without hope)
thankful (full of thanks) vs. thankless (without thanks)
powerful (full of power) vs. powerless (without power)

Spelling Rule: Adding -ly

Most adjectives: just add -ly → quickly, slowly, softly
Adjectives ending in -y: change y to i, then add -ly → happy → happily, easy → easily
Adjectives ending in -le: drop -le, add -ly → possible → possibly, gentle → gently
Adjectives ending in -ful: just add -ly (yes, double l!) → beautiful → beautifully

Word Families

A word family is a group of words that share the same root. By learning one root, you gain access to its noun, verb, adjective, and adverb forms. This is the most efficient way to expand your vocabulary.

One Root, Four Forms

Think of a word family like a family tree. The root word is the parent, and the noun, verb, adjective, and adverb forms are its children. They all share the same DNA but look slightly different.

Word Family Chart

Verb	Noun	Adjective	Adverb
create	creation, creator	creative	creatively
succeed	success	successful	successfully
decide	decision	decisive	decisively
communicate	communication	communicative	communicatively
attract	attraction	attractive	attractively
imagine	imagination	imaginative	imaginatively
differ	difference	different	differently
depend	dependence	dependent	dependently

Practice: Complete the Word Family

Click each item to reveal the missing forms.

1. Verb: educate → Noun: ? → Adjective: ? → Adverb: ? ▼

2. Verb: employ → Noun: ? → Adjective: ? → Person: ? ▼

3. Adjective: happy → Noun: ? → Adverb: ? → Opposite adjective: ? ▼

4. Verb: develop → Noun: ? → Person: ? → Adjective: ? ▼

5. Verb: compete → Noun (event): ? → Noun (person): ? → Adjective: ? ▼

Practice & Common Mistakes

Word formation errors are among the most frequent mistakes in English writing. Many of these come from applying the wrong suffix, misspelling the transformation, or inventing forms that do not exist.

Common Word Formation Errors

Wrong	Correct	Why
successfull	successful	-ful has only one "l" as a suffix
importancy	importance	The correct suffix is -ance, not -ancy
beautifull	beautiful	-ful always has one "l" (but beautiful-ly has double l)
informations	information	"Information" is uncountable — no plural form
definately	definitely	From "definite" + -ly, not "definate"
occured	occurred	Double the final consonant: occur → occurred
arguement	argument	Drop the -e from "argue" before adding -ment
responsable	responsible	The correct suffix is -ible, not -able

The "-ful" Rule

The word "full" has two l's, but the suffix -ful always has just one l. Think of it this way: when "full" joins a word, it loses one "l" to make room.

beautiful (not beautifull) | wonderful (not wonderfull) | successful (not successfull)

However, when you then add -ly, the word naturally gets "ll": beautiful + ly = beautifully.

Exercise: Correct the Mistakes

Each sentence contains a word formation error. Click to reveal the correction.

1. The goverment announced new policies. ▼

2. She is very knowledgable about history. ▼

3. His performence was outstanding. ▼

4. The childrens were very happy. ▼

5. We need to find a solvation to this problem. ▼

Exercise: Fill in the Correct Form

Use the word in brackets to form the correct word for each sentence.

1. His __________ of the topic impressed the panel. (know) ▼

2. The project was completed __________. (success) ▼

3. There is no __________ between the two reports. (similar) ▼

4. She spoke very __________ about her experiences. (emotion) ▼

5. The __________ of the new bridge took three years. (construct) ▼

6. It is __________ to drive without a licence. (legal + negative prefix) ▼