subject + be + adjectiveAfter be and similar verbs, choose the adjective form, not the noun or verb.
Adjective Suffixes
B1Use common suffixes to build adjectives: -ful, -less, -ive, -al, -ous, -able. They help you describe people, things, and situations in the right form.
What you'll learn
- Build adjectives with -ful and -less.
- Build adjectives with -ive, -al, -ous, and -able.
- Choose the adjective form after be.
- Choose the adjective form before a noun.
- Recognize meaning clues in common adjective endings.
Structure
article + adjective + nounBefore a noun, use the adjective form to describe it.
Build a sentence
Base word
Target adjective
help→helpful
Anna gave me helpful advice.
Use -ful to build the adjective: help → helpful.
When to use
Describing things
Use suffix adjectives to describe objects, plans, places, and situations: a useful app, a dangerous road, a comfortable chair.
After be
Use the adjective after be, seem, look, or feel: The room is spacious. The plan seems practical.
Guessing meaning
Use the suffix as a clue when you meet a new word. painless suggests without pain; washable suggests it can be washed.
Markers
-ful-less-ive-al-ous-able
Spelling
noun + -ful
→ one l in -fulhelp → helpfulnoun + -less
→ + lesscare → carelessverb + -able
→ base + ablewash → washableCommon mistakes
Wrong
The map was useless, so we found the hotel quickly.
Correct
The map was useful, so we found the hotel quickly.
-less changes the meaning to without. Here the sentence needs a positive meaning, so use useful.
Wrong
Tom sent a helpfull message.
Correct
Tom sent a helpful message.
The suffix is -ful with one l, not -full.
Wrong
The meeting was success.
Correct
The meeting was successful.
After was, use an adjective to describe the meeting.
Wrong
We stayed in a comfort hotel.
Correct
We stayed in a comfortable hotel.
Before a noun, use the adjective form comfortable, not the base noun comfort.
Wrong
These shoes are comfortive.
Correct
These shoes are comfortable.
Not every base word takes every suffix. Learn the finished adjective form: comfortable.
Common misconceptions
❝ I can add any adjective ending to a word if the meaning feels clear. ❞
English uses fixed word families. Some forms are common and correct, and others are not used at all.
❝ After be, a related noun is fine if people understand the meaning. ❞
After be, English normally needs the adjective form for description: useful, official, dangerous, successful.
Skills in this rule (5)
ADD_FUL_LESSw5Build adjectives with -ful and -less
Use -ful to show that something has a quality and -less to show that it does not have it. These endings often turn a noun into an adjective.
ADD_IVE_AL_OUS_ABLEw5Build adjectives with -ive, -al, -ous, and -able
Use common endings to turn verbs or nouns into adjectives: -ive, -al, -ous, and -able. Learn the finished adjective as a word you can use before a noun or after be.
USE_ADJECTIVE_AFTER_BEw4Choose the adjective form after be
After be, use an adjective, not a noun or verb. Suffix adjectives often appear in patterns like is useful, seems dangerous, or looks practical.
USE_ADJECTIVE_BEFORE_NOUNw4Choose the adjective form before a noun
Before a noun, use the adjective form that describes it: a useful tool, an official email, a dangerous road. Do not leave the base noun there.
RECOGNIZE_COMMON_SUFFIX_MEANINGSw3Recognize what common adjective endings often mean
-ful often means full of, -less means without, and -able often means can be. These meaning clues help you choose the right adjective in context.