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English grammar

CEFR B1-B2

Test yourself (24 questions)

Word formation in English: how suffixes build word families and give away the part of speech

By this point in the course you know a couple of thousand English words. Here is the good news: you know far more than that, because English builds words in families. Learn hope and you have already half-learned hopeful, hopeless and hopefully. The machinery that builds the family is the suffix - a short ending that changes what job the word does without changing what it is about.

Suffixes pay you twice. Once when you speak, because one learned root gives you a noun, an adjective and an adverb for the price of one. And once when you read, because the suffix tells you a word's part of speech even when you have never seen the word before. You do not need to know what steadiness means to know it is a noun, and knowing it is a noun is most of the battle.

One root, one family

Take care and watch it change jobs:

WordJobExample
carenoun/verbShe takes care of the garden.
carefuladjectiveBe careful with that glass.
carelessadjectiveA careless mistake.
carefullyadverbHe carried the box carefully.

Same idea, four words. The root carries the meaning; the suffix carries the grammar. Every section below is one branch of this system.

The noun suffixes: -ness, -ment, -tion

These three endings build nouns, and between them they cover an enormous share of the abstract nouns you will meet.

-ness attaches to adjectives. The noun means the quality of being that adjective:

  • dark - darkness: He could not see anything in the darkness.
  • kind - kindness: Thank you for your kindness.
  • ill - illness: She is away with an illness.
  • happy - happiness (note the spelling: y becomes i)

-ment attaches to verbs. The noun means the act or result of the verb:

  • move - movement: She noticed a movement behind the door.
  • agree - agreement: The two sides reached an agreement.
  • pay - payment: You can make the payment by card.
  • arrange - arrangement: We have an arrangement with the hotel.

-tion (and its sister -sion) also attaches to verbs, and it is the most common noun ending in the language:

  • invite - invitation: Did you get an invitation?
  • inform - information: We need more information.
  • decide - decision: It was a hard decision.
  • react - reaction: His reaction surprised everyone.

Which verb takes -ment and which takes -tion? There is no rule worth learning. Nobody works out payment from first principles; you meet it, you keep it. What matters is the direction you read it in: see -ment or -tion on the end of anything and you are looking at a noun.

The adjective suffixes: -ful, -less, -able

-ful means full of. Hopeful is full of hope, useful is full of use, painful is full of pain. One warning that catches even strong learners: the suffix is spelled with one l. Careful, not carefull. The word full keeps both, the suffix keeps one.

-less means without. It is the mirror of -ful: hopeless, useless, careless, homeless. The pair does not always exist on both sides - English has homeless but not homeful - but when both exist they are exact opposites: a careful driver and a careless one.

-able means it can be done. Washable can be washed, readable can be read, acceptable can be accepted. This is the suffix behind comfortable and available, and it is still alive: English speakers invent -able words freely, and everyone understands them, because the suffix does the work.

The adverb suffix: -ly

Add -ly to an adjective and you get the adverb: quick - quickly, slow - slowly, quiet - quietly. Three spelling notes:

  • y becomes i: happy - happily, easy - easily
  • adjectives ending in -le drop the e: simple - simply
  • adjectives ending in -ic take -ally: basic - basically

Two traps live here, and both are worth knowing at this level.

Trap one: some -ly words are adjectives. Friendly, lovely, lonely and silly all end in -ly and none of them is an adverb: a friendly dog, a lovely morning. You cannot say she smiled friendly; English speakers say she gave me a friendly smile instead.

Trap two: some adverbs refuse -ly. Fast, hard, late and well do the adverb job with no suffix: he drives fast, she works hard, he arrived late. And the -ly forms that look related have wandered off to other meanings: hardly means almost not (he hardly works - he does very little), and lately means recently (have you seen her lately?). He works hardly is not English.

The verb suffix: -en

The smallest family, but a neat one. Add -en to a short adjective and you get a verb meaning make or become more of it:

  • dark - darken: The sky darkened before the storm.
  • short - shorten: They want to shorten the meeting.
  • wide - widen: They are widening the road.
  • soft - soften: Her voice softened.

It only works with a limited set of adjectives, most of them one syllable. Do not build new ones - greenen is not a word - but recognise the pattern when you meet it.

Spot the suffix, know the job

Here is the reading strategy this whole page has been building towards. Take a sentence with a word you do not know:

The brightness of the light surprised her.

You may never have met brightness, but the -ness ending tells you it is a noun, and the root bright tells you roughly what it is about. Suffix plus root plus position in the sentence, and the word has nowhere to hide. This is what fluent readers are actually doing when they seem to know every word: they are not remembering, they are decoding.

Turn the strategy around when you write. If the sentence needs a noun, do not reach for the adjective and hope: the movement of the crowd, not the move of the crowd... and definitely not the moveness.

Common mistakes

Ranked by how often learners actually make them.

  1. Adjective where the noun belongs. Thank you for your kind should be thank you for your kindness. After your, the or a, English wants the noun form.
  2. Adjective doing an adverb's job. She sings beautiful should be she sings beautifully. If it describes the verb, it needs the adverb.
  3. Double l on -ful. Carefull and usefull are misspellings. The suffix has one l: careful, useful.
  4. Hardly as the adverb of hard. He works hardly means almost the opposite of he works hard. Hardly means almost not, and the mistake reverses your meaning entirely.
  5. Inventing the wrong noun. Agreement exists but agreeness does not; darkness exists but darkment does not. When in doubt, check - the suffix system is regular to read but irregular to build.
  6. Treating friendly as an adverb. He spoke to me friendly should be he spoke to me in a friendly way. Adjective in -ly, so English routes around it with in a ... way.

Practice

Complete each sentence with the right form of the word in brackets. Answers are below.

  1. There was a strange ___ in the box. (move)
  2. The instructions were completely ___. (use + without)
  3. She answered all the questions ___. (easy)
  4. The days ___ in the winter. (short)
  5. His ___ made the whole team feel welcome. (kind)

Answers: 1. movement 2. useless 3. easily 4. shorten 5. kindness

Suffixes are one half of English word-building; the other half is knowing which form a verb takes after another verb, which is the territory of gerund and infinitive. And the adjective-or-adverb question comes back with real money on the table in comparatives and superlatives.

Practise: test yourself

Pick the right one

0/8

Choose the word that completes each sentence.

  1. He could not see anything in the .

  2. You can make the by card.

  3. Did you get an to the party?

  4. Be with that glass.

  5. The charity helps people find somewhere to live.

  6. This chair is old but very .

  7. He opened the door .

  8. They want to the road.

Fill in the blank

0/8

Build the new word from the word given.

  1. Make a noun from ill:

  2. Make a noun from agree:

  3. Make a noun from invite:

  4. Make an adjective from use that means full of use:

  5. Make an adjective from hope that means without hope:

  6. Make an adjective from accept:

  7. Make an adverb from happy:

  8. Make a verb from short:

Matching

0/8

Match each suffix to the job it does.

Frequently asked questions

What is a suffix in English?
A suffix is an ending added to a word that changes its job in the sentence. Add -ness to the adjective kind and you get the noun kindness. Add -ly and you get the adverb kindly. The core meaning stays the same; only the grammar changes. English builds whole word families this way: one root, four or five words.
How do I know if an English word is a noun, an adjective or an adverb?
Look at the ending. Words ending in -ness, -ment or -tion are almost always nouns: darkness, movement, information. Words ending in -ful, -less or -able are almost always adjectives: hopeful, useless, comfortable. Words ending in -ly are usually adverbs: quickly, slowly. The suffix tells you the job even when you have never met the word before, which is exactly why suffixes are worth learning.
What is the difference between -ness, -ment and -tion?
All three make nouns, but from different roots. -ness attaches to adjectives: dark becomes darkness, ill becomes illness. -ment and -tion attach to verbs: move becomes movement, agree becomes agreement, decide becomes decision, invite becomes invitation. There is no rule that tells you which verb takes which ending; you learn payment and information as words, not as formulas. The useful part is reading them, not building them.
Do all English adverbs end in -ly?
No, and not everything ending in -ly is an adverb. Fast, hard, well and late are adverbs with no -ly at all: he drives fast, she works hard. Meanwhile friendly, lovely, lonely and silly end in -ly but are adjectives: a friendly dog. And hardly is not the adverb of hard; it means almost not. He hardly works means he does very little work.