Building words like a builder
Many English words are built from smaller word parts. If you know what the parts mean, you can figure out thousands of words, even ones you have never seen.
Look at unhelpful:
- un- = not
- help = to assist
- -ful = full of
So unhelpful means “not full of help,” or not helpful.
The middle part, help, is the base word. The part at the start is a prefix. The part at the end is a suffix. Prefixes and suffixes together are called affixes.
Prefixes
A prefix is added to the beginning of a base word. It changes the word’s meaning.
| Prefix | Meaning | Examples |
|---|---|---|
| un- | not, opposite of | unhappy, unlock, unfair |
| re- | again, back | redo, rewrite, return |
| dis- | not, opposite of | disagree, dislike, disappear |
| pre- | before | preview, preheat, prepay |
| mis- | wrongly | misspell, misplace, misunderstand |
| non- | not | nonfiction, nonstop, nonsense |
| in-, im- | not | incorrect, impossible, impolite |
| over- | too much | overeat, overflow, overdue |
| sub- | under, below | submarine, subway, subzero |
| inter- | between | international, interact |
Notice: un-, dis-, non-, in- and im- can all mean “not.”
Suffixes
A suffix is added to the end of a base word. It can change the meaning and often changes the word’s part of speech (whether it is a noun, verb, adjective or adverb).
| Suffix | Meaning | Examples | Makes a… |
|---|---|---|---|
| -ful | full of | careful, joyful | adjective |
| -less | without | careless, fearless | adjective |
| -ly | in a certain way | quickly, sadly | adverb |
| -er, -or | a person who | teacher, actor | noun |
| -ness | state of being | kindness, darkness | noun |
| -ment | act or result of | enjoyment, payment | noun |
| -able, -ible | can be done | readable, flexible | adjective |
| -tion, -sion | act or process | celebration, decision | noun |
| -er, -est | more, most | faster, fastest | adjective |
| -ed, -ing | past, ongoing action | jumped, jumping | verb |
Example: teach (verb) + -er = teacher (noun). Kind (adjective) + -ness = kindness (noun).
Spelling changes with suffixes
Adding a suffix sometimes changes the spelling of the base word.
- Drop the silent e before a vowel suffix: hope + -ing = hoping; care + -ing = caring. But keep it before a consonant suffix: care + -ful = careful.
- Change y to i after a consonant: happy + -ness = happiness; beauty + -ful = beautiful.
- Double the final consonant in short words with one vowel: run + -ing = running; big + -est = biggest.
Prefixes almost never change spelling: mis + spell = misspell (yes, two s’s!).
How to use word parts to read a new word
- Look for a prefix at the beginning. Cover it.
- Look for a suffix at the end. Cover it.
- Read the base word that is left.
- Put the meanings together, starting with the base.
- Check the meaning in the sentence.
Worked examples
Example 1: reusable
re- (again) + use + -able (can be) = can be used again.
Bring a reusable bag to the store.
Example 2: disrespectful
dis- (not) + respect + -ful (full of) = not showing respect.
Example 3: preheat
pre- (before) + heat = to heat before.
Preheat the oven before you put in the cookies.
Example 4: fearlessly
fear + -less (without) + -ly (in a way) = in a way without fear.
The firefighter fearlessly entered the building.
Example 5: misunderstanding
mis- (wrongly) + understand + -ing = understanding wrongly; a mix-up.
Watch out for look-alikes
Not every word that starts with re or un has a prefix. In reach and uncle, the letters are just part of the word. Test it: if you cover the “prefix,” is a real base word left? Re-ach: “ach” is not a word, so re is not a prefix here.
Common mistakes
- Mixing up opposite suffixes. Careful means full of care; careless means without care.
- Spelling errors with suffixes. Hopeing should be hoping; happyness should be happiness.
- Finding false prefixes. Always check that a real base word remains.
- Forgetting the part of speech. Quick is an adjective; quickly is an adverb. Use the one the sentence needs.
Try it yourself
- What does unbreakable mean?
- Add a prefix to make the opposite: agree, possible, lock.
- Add a suffix to make a noun: kind, move, act.
- Spell it: happy + -ly, hope + -ful, swim + -ing.
- Is re a prefix in ready? How do you know?
Answers: 1. Not able to be broken. 2. disagree, impossible, unlock. 3. kindness, movement, action (or actor). 4. happily, hopeful, swimming. 5. No; ady is not a base word.
Study tip
Make a set of cards with prefixes in one colour, base words in another and suffixes in a third. Mix and match to build real words, then write a sentence for each one.
Quick recap
- Prefixes go at the beginning; suffixes go at the end.
- The base word is the part that can stand alone.
- Prefixes change meaning; suffixes change meaning and often the part of speech.
- Watch for spelling changes when you add suffixes.
- Break unknown words into parts and put the meanings together.