Adjective Forms

B1 · IntermediateAdjectives

Recognizing a handful of adjective-forming endings and negative prefixes lets you understand — and build — hundreds of adjectives you've never memorized individually.

What you'll learn

  • -ful (full of) vs -less (without): helpful / careless
  • -ous, -able/-ible, -ive, -al, -y, -ic: common adjective-forming suffixes
  • Negative prefixes: un-, in-, im-, dis-, ir- — the prefix depends on the word
  • There's no single reliable rule for which negative prefix a word takes — it has to be learned per word

Building adjectives from other words

Many English adjectives are built from a noun or verb plus a suffix. Once you recognize the suffix, you can often guess the meaning of an adjective you've never seen before — and use the pattern to build new ones.

-ful (full of) vs -less (without)

These two suffixes are opposites: -ful means 'having' or 'full of' that quality; -less means 'without' it. Care + ful = careful (having care); care + less = careless (without care).

"She's a very careful driver."
"That was a careless mistake."

Other common adjective suffixes

-ous: danger → dangerous, fame → famous. -able/-ible: afford → affordable, response → responsible. -ive: create → creative, act → active. -al: nation → national, culture → cultural. -y: rain → rainy, sun → sunny. -ic: economy → economic, history → historic.

"This road is dangerous."
"She's a very creative person."
"It was a rainy afternoon."

Making an adjective negative

To reverse an adjective's meaning, English uses several different negative prefixes: un- (unhappy, unfair), in- (inexpensive, invisible), im- (impossible, impatient — before p/m/b), dis- (dishonest, disloyal), ir- (irregular, irresponsible — before r).

There's no rule that predicts which prefix a specific word uses — un- is the most common by far, but you simply have to learn the exceptions (impossible, not unpossible; irregular, not inregular) as you meet them.

"It's completely impossible."
"That was a dishonest answer."
"The pattern is irregular."

Real English

"He gave a really thoughtful answer."
"This app is surprisingly affordable."
"It's a fairly informal event, so don't overdress."
"Her explanation was completely illogical."

Watch out

✗This puzzle is unpossible to solve.
✓This puzzle is impossible to solve.

Possible takes im-, not un- — there's no shortcut rule, these have to be memorized individually.

✗This job is very dangerful.
✓This job is very dangerous.

Danger takes the suffix -ous, not -ful — -ful attaches to a specific, smaller set of nouns.

✗She is a very carefully driver.
✓She is a very careful driver.

Before a noun, you need the adjective form (careful), not the -ly adverb form (carefully).

✗This is an unimpossible task.
✓This is an impossible task.

Never stack two negative prefixes on one word — choose the one correct prefix for that specific word.

Real life — Reviewing an apartment listing

"So what did you think of the place?"

"It seemed nice — spacious, and the price was pretty reasonable."

"Anything you didn't like?"

"Honestly, the location felt a bit unsafe at night."

Practice

Exercise 1 · Choose the correct suffix

care + ___ = full of care

Exercise 2 · Choose the correct suffix

care + ___ = without care

Exercise 3 · Choose the correct adjective

This job is very ___. (danger + suffix)

Exercise 4 · Choose the correct adjective

This chair is really ___. (comfort + suffix)

Exercise 5 · Choose the correct negative form

Choose the negative form of happy:

Exercise 6 · Choose the correct negative form

Choose the negative form of possible:

Exercise 7 · Fix the mistake

Fix the mistake:

Exercise 8 · Complete the word

Complete: add -ous to 'fame' to get an adjective meaning 'well-known'. (one word)

Exercise 9 · Complete the word

Complete: add the negative prefix to 'regular' (the prefix changes spelling). (one word)

Exercise 10 · Sort the adjectives into groups

helpful
hopeless
careful
careless
fearless
joyful

0 / 6 sorted

Exercise 11 · Choose the correct negative form

Choose the correct negative form of honest:

Quick challenge

Five quick questions to check what stuck.

Question 1 / 5

Score: 0/0

Add -able to 'afford' to get an adjective.

You learned

  • -ful means 'full of'; -less means 'without' — they're opposites.
  • -ous, -able/-ible, -ive, -al, -y and -ic are common adjective-forming suffixes.
  • Negative prefixes include un-, in-, im-, dis- and ir- — which one a word takes has to be learned individually.
  • Never use the -ly adverb form (carefully) where an adjective (careful) is needed before a noun.

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Learn the difference between adjectives like bored and boring — -ed describes how someone feels, -ing describes the thing or situation that causes the feeling.

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