Word Formation: Prefixes, Suffixes and Roots
Word Formation: Prefixes, Suffixes and Roots
Word formation closes the vocabulary chapter and gives 1 to 2 questions, but its real value is larger: knowing roots lets you decode unfamiliar words in every other vocabulary question. It is the one topic in this chapter that multiplies the others.
Prefixes Change Meaning
| Prefix | Meaning | Example |
|---|---|---|
| un-, in-, im-, ir-, il-, dis- | not | unfair, incorrect, impossible, irregular, illegal, disagree |
| re- | again | rewrite, reconstruct |
| pre- | before | prehistoric, prepaid |
| post- | after | postgraduate, postpone |
| mis- | wrongly | misunderstand, misuse |
| sub- | under | submarine, subordinate |
| super- | above | supervise, superhuman |
| anti- | against | antisocial, antiseptic |
| auto- | self | autobiography, automatic |
| mono-, bi-, tri-, poly- | one, two, three, many | monologue, bilingual, tricycle, polyglot |
The negative prefixes follow the sound that comes after them: im- before p, b and m (impossible, imbalance, immortal); ir- before r (irregular); il- before l (illegal); in- elsewhere. That pattern is a rule, not a list, and it is worth knowing as one.
✗ Inpossible and inlegal | ✓ Impossible before p, illegal before l
Suffixes Change Word Class
| Suffix | Forms | Example |
|---|---|---|
| -ness, -ity, -ment, -tion | Nouns | kindness, ability, judgement, action |
| -er, -or, -ist, -ian | Person nouns | teacher, actor, novelist, historian |
| -ful, -less, -ous, -ive | Adjectives | hopeful, hopeless, famous, active |
| -ise, -ify, -en | Verbs | modernise, simplify, strengthen |
| -ly | Adverbs | quickly, hardly |
A question may give a word and ask for its noun or adjective form, so practise converting in both directions: able → ability → unable → inability. Note that -ly does not always make an adverb: friendly, lovely, cowardly are adjectives, and that exception is asked.
Roots Unlock Unfamiliar Words
| Root | Meaning | Words |
|---|---|---|
| bio | life | biology, biography, antibiotic |
| graph, gram | write | autograph, telegram, calligraphy |
| scrib, script | write | describe, manuscript, inscription |
| dict | say | predict, dictate, verdict |
| port | carry | transport, portable, export |
| spect | look | inspect, spectator, prospect |
| chron | time | chronology, synchronise, anachronism |
| phil | love | philosophy, philanthropist, bibliophile |
Combine a root with a prefix and a suffix and an unknown word becomes readable. Anachronism is ana against plus chron time plus ism — something out of its time. That decoding is exactly the skill the synonym and one-word-substitution questions reward.
This is why word formation is worth doing first rather than last in the vocabulary chapter: thirty roots learnt properly make several hundred words guessable, which changes what happens when you meet a word you have never seen.
उपसर्ग अर्थ बदलता है, प्रत्यय शब्द-श्रेणी।
TRE pointer: This topic pays twice. Directly, it gives 1 to 2 questions on prefix, suffix or root. Indirectly, it is what lets you attempt a synonym question on a word you have never seen — and in a five-option paper with −1/3 for a wrong answer, turning a pure guess into a reasoned elimination is worth more than any single fact. The im-, ir-, il- sound rule and the -ly adjective exception are the two direct items.
60-Second Recap
- Prefixes change meaning; suffixes change word class; roots carry the core sense.
- im- before p, b, m; ir- before r; il- before l; in- elsewhere.
- -ness, -ity, -ment, -tion form nouns; -ise, -ify, -en form verbs.
- Friendly, lovely, cowardly end in -ly but are adjectives.
- Roots: bio life, graph write, dict say, port carry, spect look, chron time, phil love.
- Thirty roots learnt well make several hundred unfamiliar words readable.
Frequently Asked Questions
Why is it impossible but irregular?
Because the negative prefix changes to match the sound that follows. It becomes im before p, b and m, ir before r, il before l, and stays in elsewhere. This is a pronunciation rule rather than an arbitrary list, so it can be applied to new words.
Do all words ending in -ly function as adverbs?
No. Friendly, lovely, cowardly, lonely and likely all end in -ly but are adjectives. The suffix usually forms adverbs from adjectives, as with quick and quickly, but these exceptions are asked precisely because the general rule is so widely assumed.
How do roots help in a vocabulary question?
They let you decode a word you have never seen. Anachronism breaks into ana meaning against, chron meaning time and ism, giving something out of its proper time. Around thirty common roots make several hundred unfamiliar words at least partly readable.
Which should I learn first, roots or word lists?
Roots. A word list gives you exactly the words on it, while thirty roots let you make sense of hundreds of words you have not met, including in the comprehension passage. Roots also make the words on any list far easier to remember.
Next step: Vocabulary is built by testing, not by reading lists. Practise this chapter in the BPSC TRE 4.0 mock test on ExamAtlas — five options, −1/3 negative marking, and graduate-level words.