Word formation
Prefixes, suffixes, compounds and phrasal verbs
Word formation is the way new words are built from existing words or roots. The two most common methods are adding a prefix to the beginning of a word and adding a suffix to the end of it. Prefixes usually change the meaning of a word, especially negative prefixes such as un-, in-, im-, il-, ir-, dis- and non-, which give the opposite meaning (happy → unhappy). Suffixes usually change the part of speech: noun-forming suffixes (-tion, -ness, -ment, -ity, -er, -ist), adjective-forming suffixes (-ful, -less, -able, -ous, -ive, -y), the adverb-forming suffix -ly, and verb-forming suffixes (-ise/-ize, -en). English also forms words by joining two words into a compound (blackboard, classroom) or by combining a verb with a particle to make a phrasal verb (give up = stop, look after = take care of). The correct prefix or suffix depends on the base word, so each form must be learned, not guessed. For example: from the adjective 'care' we form 'careful' (adjective), 'carefully' (adverb) and 'careless' (the opposite quality).
Key terms
| Suffix | Makes (part of speech) | Example |
|---|---|---|
| -tion | noun | explain → explanation |
| -ment | noun | enjoy → enjoyment |
| -ful | adjective | use → useful |
| -less | adjective | hope → hopeless |
| -ous | adjective | danger → dangerous |
| -ly | adverb | quick → quickly |
| Prefix | Meaning | Example |
|---|---|---|
| un- | negative (not / opposite) | happy → unhappy |
| in- | negative (not) | (im- before p, m, b: impossible) |
| dis- | negative (opposite) | agree → disagree |
| re- | again | write → rewrite |
| mis- | wrongly | understand → misunderstand |
- 1Start with the base word: The base word is 'use'.
- 2Decide the part of speech you need: The sentence 'This bag is very ___' needs an adjective after 'very'.
- 3Choose the suffix: The adjective-forming suffix -ful means 'full of', so 'use' + -ful = 'useful'.
- 4Answer: useful (adjective). Note that 'usefully' would be an adverb (-ly) and 'useless' would mean the opposite.
- 1Look at the suffix: Compare 'decision', 'decisive' and 'decidedly'.
- 2Match each suffix to a word class: -tion forms a noun (decision), -ive forms an adjective (decisive), -ly forms an adverb (decidedly).
- 3Pick what the sentence needs: To form a noun from the verb 'decide', choose the -tion form.
- 4Answer: decision (noun).
After 'very' or before another verb the sentence needs an adjective, not an adverb. Write 'This bag is very useful', not 'usefully' — the -ly form is an adverb.
The negative prefix changes shape before some letters: use im- before p, m or b (impossible, impolite), il- before l (illegal), and ir- before r (irregular). 'Inpossible', 'unlegal' and 'inregular' are wrong.
Do not invent words. Forms like 'singful', 'cloudly', 'dangerful' or 'misagree' are not real English — the correct words are 'singer', 'cloudy', 'dangerous' and 'disagree'.
Watch spelling when you add -ly to a word ending in -e: 'true' drops the 'e' to make 'truly', not 'truely'.
Rules
- 1Prefixes change meaning; the negative prefixes are un-, in-, im- (before m/p/b), il- (before l), ir- (before r), dis- and non-.
- 2Suffixes change word class: -tion/-ness/-ment/-ity form nouns, -ful/-less/-able/-ous/-ive form adjectives, -ly forms adverbs, -ise/-ize/-en form verbs.
- 3A person/agent is often formed with -er, -or or -ist (teach → teacher, act → actor, art → artist).
- 4A compound word joins two words into one new word (black + board → blackboard).
- 5A phrasal verb is a verb plus a particle whose meaning is often different from the single verb (give up = stop, look after = take care of).
Practice
15 easy · 15 medium · 15 hard
10 random questions per test