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REET L1+L2 · English (Language I/II)

Word Formation: Prefixes, Suffixes, Noun–Adjective–Verb Forms and Ways Words Are Built

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This page covers every major way English builds new words — prefixes, suffixes, compounding, conversion, clipping, blending, acronyms and back-formation — along with a useful list of noun, verb, adjective and adverb forms. REET 2024 carried 5 questions on this topic, all about identifying a word's form or its base word.

  • 5 questions in REET 2024
  • Class 6–10 grammar level
  • 7-minute read
Verified 17 September 2026 · Source: Word formation — English Grammar Today, Cambridge Dictionary

How REET asks this topic

All 5 REET 2024 questions on this topic were direct and word-based: the noun form of 'discover' (discovery), the adjective form of 'intention' (intentional), what kind of pair 'danger–dangerous' is (noun–adjective), what 'cultivation' is formed from (cultivate), and the base word of 'erosion' (erode). The options planted similar-looking words (invention, culture), misspellings (intentionaly), and words from a different word class (intentionally = adverb). So the key to success is reading the suffix to identify the word class, and knowing the correct spelling of the base word.

What Word Formation Is

Word formation is the process by which a new word is built from an existing word or word-part. The core part of a word to which a prefix or suffix is attached is called the root or base word — in unhappiness, happy is the base word, un- is the prefix and -ness is the suffix.

The most important distinction to remember: a prefix (added at the start of a word) usually only changes the meaning, not the word class — happy (adj) → unhappy (adj). A suffix (added at the end) usually does change the word class — happy (adj) → happiness (noun), danger (noun) → dangerous (adj), discover (verb) → discovery (noun). That's exactly why REET questions about a word's 'noun form' or 'adjective form' are built around suffixes. A few prefixes do change the word class too, such as en-: danger (noun) → endanger (verb), able (adj) → enable (verb).

Major Prefixes

PrefixMeaningExample
un-, in-, dis-, non-not / oppositeunhappy, incorrect, dishonest, non-violent
im- (before p, b, m)notimpossible, imbalance, immature
il- (before l), ir- (before r)notillegal, illiterate, irregular, irresponsible
mis-wronglymisuse, misunderstand, mislead
re-againrewrite, rebuild, reopen
pre-, post-before / afterprehistoric, preview, postwar
over-, under-too much / too littleoverload, underestimate
sub-, inter-, trans-under / between / acrosssubway, international, transport
co-, anti-together / againstco-operate, antibiotic
en-to make/cause (forms verbs)enrich, enlarge, endanger

Identifying Word Class from Suffix

Form producedMain suffixesExample
Noun-tion/-sion, -ment, -ness, -ity, -ance/-ence, -y, -dom, -hood, -ship, -er/-orcultivation, erosion, movement, kindness, ability, importance, discovery, freedom, childhood, friendship, teacher
Adjective-ous, -ful, -less, -able/-ible, -al, -ive, -y, -ish, -icdangerous, useful, careless, readable, intentional, active, windy, childish, poetic
Verb-ise/-ize, -en, -ify, -atemodernise, widen, beautify, activate
Adverb-ly, -wards, -wiseintentionally, backwards, clockwise

Caution: -ly doesn't always signal an adverb — friendly, lovely, lonely are adjectives. So check how the word is actually used as well.

Noun – Verb – Adjective – Adverb Forms (an exam-useful list)

NounVerbAdjectiveAdverb
discoverydiscoverdiscoverable—
intentionintendintentionalintentionally
dangerendangerdangerousdangerously
cultivationcultivatecultivated / cultivable—
erosionerodeerosive—
decisiondecidedecisivedecisively
beautybeautifybeautifulbeautifully
strengthstrengthenstrongstrongly
widthwidenwidewidely
successsucceedsuccessfulsuccessfully
knowledgeknowknowledgeableknowledgeably
courageencouragecourageouscourageously
abilityenableableably
continuitycontinuecontinuouscontinuously

A '—' means that word class has no commonly used form.

Other Ways New Words Are Built

ProcessMeaningExample
CompoundingJoining two independent wordsblackboard, sunflower, toothbrush, classroom, mother-in-law
ConversionChanging a word's class with no change in forma walk (noun) → to walk (verb); an email → to email
ClippingShortening a longer wordexamination → exam, telephone → phone, laboratory → lab
BlendingMerging parts of two wordssmoke + fog → smog, breakfast + lunch → brunch, motor + hotel → motel
AcronymA word formed from initial letters, pronounced as a wordNASA, UNESCO, radar (radio detection and ranging)
Back-formationRemoving a suffix from a longer established word to make a shorter oneeditor → edit, television → televise

Spelling Rules When Adding a Suffix

(1) A silent 'e' at the end of a word usually drops before a suffix that begins with a vowel — cultivate → cultivation, erode → erosion (here d also changes to s), decide → decision; but it usually stays before a suffix beginning with a consonant — hope → hopeful, move → movement. A few exceptions exist: argue → argument, true → truly.

(2) In a word ending in consonant + y, the y changes to i — happy → happiness, beauty → beautiful; but it doesn't change after a vowel + y — enjoy → enjoyment. (3) In a short word ending in one vowel + one consonant, the final consonant is doubled — begin → beginning, run → runner. (4) Forming an adverb from a -al or -ful adjective adds -ly, so a double 'l' results — intentional → intentionally, careful → carefully; 'intentionaly' is a misspelling.

How to Teach This to Children

Classes 3–5: The word-family tree

Draw a tree on a chart with the base word (help) at the root and helpful, helper, helpless, unhelpful on the branches. Children make their own trees and display them in class.

Classes 6–8: Suffix sorting

Have children sort word slips (kindness, useful, widen, slowly) into four boxes — Noun, Adjective, Verb, Adverb. Then let them work out the suffix rule themselves (the inductive method).

Prefix game

'Make the opposite': the teacher says possible, legal, regular, honest and teams attach the right negative prefix. Let them work out the im-/il-/ir- rule by looking at the letters.

Teaching aids

Three-coloured prefix–root–suffix cards, a word wheel, and dictionary use (recognising the abbreviations n., v., adj., adv. for word class).

Common misconceptions

Treating every -ly word as an adverb (friendly), mixing up the nouns of discover and invent, misspellings like intentionaly, and adding un-/in- arbitrarily (unpossible).

Assessment idea

Give a short paragraph in which the correct form of a bracketed word must be filled in — 'The ___ (discover) of fire changed human life.' This tests both word class and contextual understanding.

Memory trick / exam tip

Before choosing an answer, look at the word in the question — if it asks for a 'noun form', pick the option with -tion, -ment, -ness, -ity or -y; if it asks for an 'adjective', pick -ous, -ful, -al, -ive or -able; -ly is usually an adverb. If a base word is asked for, remove the suffix and bring back the silent e where needed: cultivation → cultivate, erosion → erode.

Questions asked in REET 2024 (solved)

Question 53

The noun form of the word ‘discover’ is

  1. Ainvention
  2. Bdiscovery
  3. Cdiscovered
  4. Dinvented

Explanation

क्रिया ‘discover’ में ‘-y’ प्रत्यय जोड़कर noun ‘discovery’ बनता है। ‘invention’ दूसरे शब्द (invent) का noun है, जबकि ‘discovered/invented’ क्रिया के past रूप हैं।

Question 55

‘danger-dangerous’ is a pair of

  1. Anoun-adjective
  2. Bnoun-pronoun
  3. Cnoun-adverb
  4. Dadjective-noun

Explanation

‘danger’ (खतरा) noun है और उसमें ‘-ous’ प्रत्यय जोड़ने से adjective ‘dangerous’ (खतरनाक) बनता है। अतः यह noun-adjective जोड़ी है।

Question 49

‘Cultivation’ is derived from :

  1. ACultive
  2. BCumulative
  3. CCultivate
  4. DCulture

Explanation

'Cultivation' (खेती) संज्ञा है जो क्रिया 'cultivate' में '-ion' प्रत्यय जोड़कर बनी है (cultivate → cultivation)। 'Culture' एक अलग संज्ञा है और 'Cultive' सही अंग्रेज़ी शब्द नहीं है।

Question 53

The base word for ‘erosion’ is :

  1. Aerose
  2. Brose
  3. Cerode
  4. Derise

Explanation

'Erosion' (कटाव) संज्ञा क्रिया 'erode' (कटाव करना/घिसना) से बनी है: erode → erosion। अन्य विकल्प 'erose', 'rose', 'erise' इसका मूल शब्द नहीं हैं।

Question 47

Correct adjective form of ‘intention’ is

  1. AIntentionally
  2. BIntentionaly
  3. CIntently
  4. DIntentional

Explanation

'intention' (संज्ञा) का विशेषण रूप 'Intentional' है। 'Intentionally' क्रिया-विशेषण (adverb) है, 'Intently' अलग शब्द (intent से adverb) है और 'Intentionaly' गलत वर्तनी है।

Practice questions

Question 1

The noun form of ‘decide’ is:

  1. Adecisive
  2. Bdecision
  3. Cdecided
  4. Ddecisively

Explanation

The noun formed from the verb 'decide' is 'decision'. 'decisive' is an adjective, 'decisively' an adverb, and 'decided' is the past form of the verb.

Question 2

Choose the correct opposite formed with a prefix: ‘legal’

  1. Aunlegal
  2. Binlegal
  3. Cillegal
  4. Ddislegal

Explanation

For words beginning with l, the negative prefix is usually 'il-' — legal → illegal.

Question 3

‘Widen’ is formed from the adjective ‘wide’ by adding a suffix. ‘Widen’ is a:

  1. Anoun
  2. Bverb
  3. Cadverb
  4. Dadjective

Explanation

The suffix '-en' forms a verb from an adjective (or sometimes a noun) — wide → widen, strength → strengthen.

Question 4

‘Smog’ is formed from ‘smoke’ and ‘fog’. This process is called:

  1. AClipping
  2. BCompounding
  3. CBlending
  4. DConversion

Explanation

Merging parts of two words to form a new one is blending. In compounding, both complete words are joined (blackboard).

Question 5

‘Exam’ from ‘examination’ is an example of:

  1. AClipping
  2. BAcronym
  3. CBlending
  4. DBack-formation

Explanation

Cutting a longer word down to a shorter form is clipping — examination → exam, laboratory → lab.

Question 6

Which of the following words is NOT an adverb?

  1. Aquickly
  2. Bfriendly
  3. Ccarefully
  4. Dintentionally

Explanation

Despite ending in -ly, 'friendly' is an adjective (a friendly teacher). The other three are adverbs describing how an action is done.

Question 7

The base word of ‘enjoyment’ is:

  1. Ajoy
  2. Benjoy
  3. Cenjoi
  4. Denjoyable

Explanation

'enjoyment' is formed from the verb 'enjoy' by adding '-ment'; because the word ends in vowel + y, the y does not change.

Question 8

Choose the correctly spelt adjective formed from ‘beauty’:

  1. Abeautyful
  2. Bbeautiful
  3. Cbeautifull
  4. Dbeutiful

Explanation

In a word ending consonant + y, the y changes to i before a suffix, and -ful has only one l — beautiful.

Question 9

In ‘Please email me the list’, the word ‘email’ has changed from a noun to a verb without any change in form. This is:

  1. AConversion
  2. BClipping
  3. CAffixation
  4. DBlending

Explanation

A word changing its word class without any change in form is called conversion — an email (noun) → to email (verb).

Question 10

A Class 7 teacher gives learners word cards like ‘kindness, useful, widen, slowly’ and asks them to sort the cards into four boxes and find the pattern themselves. This approach is:

  1. ADeductive
  2. BInductive
  3. CGrammar-translation
  4. DRote learning

Explanation

Letting children sort examples and find the pattern themselves is the inductive method. In the deductive method, the rule is stated first and examples follow.

Frequently Asked Questions

What is the difference between a Prefix and a Suffix?+

A prefix attaches at the start of a word and usually changes meaning (happy → unhappy), while a suffix attaches at the end and usually changes the word class (happy → happiness).

What is the noun form of 'discover'?+

The noun form of 'discover' is 'discovery'. 'Invention' is the noun of 'invent', not of 'discover'.

What is a base word or root word?+

The core part of a word to which prefixes/suffixes attach, such as erode (the base word of erosion) and cultivate (the base word of cultivation).

How many questions come from Word Formation in REET?+

REET 2024 carried 5 questions on this topic — on noun forms, adjective forms, noun–adjective pairing, and identifying base words.

Read next

Spelling

Common misspellings, silent letters and spelling rules.

One Word Substitution

One-word substitutes that come up again and again in the exam.

REET Syllabus 2026

The complete subject-wise syllabus and exam pattern for Level 1 and Level 2.

REET 2024 Solved Paper

Official questions from every shift, with the BSER answer key and explanations.

Official Sources

  1. Word formation — English Grammar Today, Cambridge Dictionary
  2. Prefixes — English Grammar Today, Cambridge Dictionary
  3. Suffixes — English Grammar Today, Cambridge Dictionary
  4. BSER — REET 2024 official question papers and final answer keys (original PDFs; no longer hosted on the board portal)

Change Log

  • 17 September 2026 — English page published — mirrors the fact-checked Hindi page, independently bilingual-accuracy checked