March 2026 · Vocabulary
Understanding how English words are built from prefixes, roots, and suffixes is one of the most powerful vocabulary-building strategies. A student who knows the prefix "un-" means "not" and the suffix "-able" means "can be done" can decode "unbelievable," "unavoidable," "uncomfortable" — and hundreds more words without ever having studied them individually.
| Prefix | Meaning | Examples |
|---|---|---|
| un- | not, opposite | unhappy, undo, unusual, unfair |
| re- | again | rewrite, redo, reconsider, rebuild |
| dis- | not, opposite | disagree, disappear, disconnect, dislike |
| mis- | wrongly | misunderstand, misspell, mislead, misuse |
| over- | too much | overwork, overcook, overreact, oversleep |
| under- | too little | underestimate, underpay, undervalue |
| pre- | before | preview, predict, prepare, preschool |
| inter- | between | international, interact, interview |
| Suffix | Function | Examples |
|---|---|---|
| -tion / -sion | verb → noun | education, decision, information |
| -ment | verb → noun | development, agreement, achievement |
| -ness | adjective → noun | happiness, kindness, darkness |
| -er / -or | person who does | teacher, actor, writer, driver |
| -ity | adjective → noun | creativity, ability, possibility |
| Suffix | Function | Examples |
|---|---|---|
| -able / -ible | can be done | comfortable, responsible, visible |
| -ful | full of | beautiful, helpful, wonderful |
| -less | without | careless, homeless, useless |
| -ous | having quality | dangerous, famous, nervous |
| -ive | having quality | creative, active, expensive |
| Suffix | Function | Examples |
|---|---|---|
| -ize / -ise | to make | organize, realize, modernize |
| -en | to make | widen, strengthen, darken |
| -ly | adjective → adverb | quickly, carefully, happily |
The classic Cambridge exam format. Provide a base word and a sentence — students transform the word to fit: "The movie was really _____. (ENJOY)" → "The movie was really enjoyable."
Students complete tables with all forms of a word: noun, verb, adjective, adverb. E.g., create | creation | creative | creatively. Great for systematic review.
Give adjectives — students add negative prefixes: happy → unhappy, possible → impossible, regular → irregular, legal → illegal. Focus on which prefix goes with which word.
Give students a root and challenge them to find all English words containing it: "port" (carry) → transport, export, import, portable, report, support, airport.
Provide a list of words. Students sort them by suffix and determine the word class (noun, adjective, verb, adverb). This reinforces the relationship between form and function.
| Error | Correct Form | Rule |
|---|---|---|
| *informations | information | Some -tion nouns are uncountable |
| *unpossible | impossible | -possible takes im-, not un- |
| *happyness | happiness | y → i before -ness |
| *beautifull | beautiful | -ful has one l, not two |
| *strongness | strength | Irregular noun form |
Introduce basic prefixes (un-, re-) and common suffixes (-er, -tion) at A2. Systematic word formation work is most effective at B1–B2, where students have enough base vocabulary to see patterns. For Cambridge exam preparation (FCE/CAE), intensive word formation practice is essential.
Group words by prefix pattern: un- is the most common negative prefix. Im-/in-/ir-/il- follow spelling patterns (im- before b/m/p, ir- before r, il- before l). Create reference charts and practice with gap-fill exercises using AI-generated worksheets.
Yes! Use the Fill in the Blanks generator with a grammar focus on word formation, or the Sentence Transformation exercise type. You can also use Negative Prefixes exercises specifically designed for prefix practice.