Topic · Prefixes & Suffixes
Read the word in two halves — and answer in 30 seconds
A prefix goes on the front and changes the meaning; a suffix goes on the end and changes the spelling and word type. In Stage 1 you pick the one right (or one wrong) version from five. Learn the join rules below and you'll spot the trap instantly.
Rule 1 Prefixes never change the root
Prefixes (dis-, mis-, un-, re-, pre-, over-, in-) just bolt onto the front. Don't add or drop letters — even if it makes a double letter.
dis + appear = disappear · mis + spell = misspell · un + necessary = unnecessary ✓
dis + satisfied = dissatisfied (double s is correct!) ✓
Rule 2 Choosing the right negative prefix
un- = not / opposite (undo, unhappy). dis- = not / reverse (dislike, disagree). mis- = wrongly / badly (misbehave, misunderstand). in-/im-/il-/ir- = not.
Use im- before m/p: impossible, immature. il- before l: illegal. ir- before r: irregular. ✓
Rule 3 The -tion / -sion / -cian ending ("shun")
The "shun" sound is usually -tion (action, station). Use -sion after l or after a vowel (tension, division); -ssion after a short root (mission, discussion); -cian for people/jobs (musician, magician).
act → action · divide → division · permit → permission · magic → magician ✓
Rule 4 -cious / -tious and -cial / -tial
The "shus" sound is -cious or -tious; the "shul" sound is -cial or -tial. Use -cial after a vowel, -tial after a consonant.
vicious, delicious · ambitious, cautious · special (after vowel) · partial (after consonant) ✓
Rule 5 -able vs -ible
Use -able when a complete root word remains (and often after a hard c/g); use -ible when the root is incomplete.
enjoy → enjoyable · comfort → comfortable (whole words) ✓
poss → possible · terr → terrible (no whole word) ✓ · Keep e for soft sound: noticeable, changeable.
Rule 6 Suffixes follow the spelling rules
A vowel suffix (-ed, -ing, -able, -ous) triggers doubling / dropping-e / y→i. A consonant suffix (-ful, -ly, -ment, -ness) leaves the root alone.
hope → hopeful (keep e) · beauty → beautiful (y→i) · argue → argument (drop e!) ✓
The 30-second method
How to crack any prefix/suffix MCQ fast
- Split the word into prefix · root · suffix. Most traps live at the join.
- Prefix? Keep the root whole — watch for the "correct" double letter (dissatisfied, misspell).
- Suffix sound? "shun" → -tion; "shus" → -cious/-tious; "shul" → -cial/-tial.
- Whole word left? Yes → usually -able. No → usually -ible.
- Eliminate the two you're sure of, then decide between the rest.
10 worked examples
Read the question, then the answer with the rule that solves it.
1. Add dis- to appear.
disappear — prefix keeps the root whole; one s (Rule 1).
2. Add mis- to spell.
misspell — prefix + root gives a correct double s (Rule 1).
3. Add un- to necessary.
unnecessary — double n is correct; never drop a root letter (Rule 1).
4. Noun from divide?
division — "shun" after a vowel takes -sion (Rule 3).
5. Which is correct: delicous / delicious?
delicious — the "shus" sound is spelt -cious (Rule 4).
6. -able or -ible: poss__?
possible — "poss" is not a whole word, so -ible (Rule 5).
7. -able or -ible: enjoy__?
enjoyable — "enjoy" is a whole word, so -able (Rule 5).
8. Add -ful to beauty.
beautiful — consonant + y becomes i before the suffix (Rules 6 & y→i).
9. Add -ment to argue.
argument — a tricky one: the e is dropped (learn this exception, Rule 6).
10. Person who does magic?
magician — jobs/people often take -cian (Rule 3).