Prefixes, suffixes and root words
English · Key Stage 2 · The School
The word inside the word
Most long words are built from a shorter ROOT with pieces added. In `unhappiness` the root is `happy`; `un-` and `-ness` are attached to it. Finding the root is the fastest way into a word you have never seen, because the root usually carries the meaning and the added pieces only adjust it.
Prefixes change the meaning
A PREFIX goes on the front. `un-`, `dis-` and `mis-` reverse or spoil something: unlock, disagree, misunderstand. `re-` means again: rebuild, return. `pre-` means before: preview, prepare. `sub-` means under: submarine, subheading. Knowing eight prefixes unlocks hundreds of words, because English keeps reusing the same small set.
Suffixes change the job
A SUFFIX goes on the end and usually changes what kind of word it is. `-ness` and `-ment` turn a describing word into a thing: kind → kindness, enjoy → enjoyment. `-ful` and `-less` turn a thing into a describing word: care → careful, careless. `-ly` turns it into how something is done: quick → quickly. Same root, different job in the sentence.
You meet 'unbreakable'. Strip the ends: un- at the front, -able at the end, leaving BREAK — a real word, so the split is right. un- means not, -able means can be. So: cannot be broken. Now try the same on 'uncle': take off un- and you have 'cle', which is not a word, so those letters are not a prefix. The test is always whether the root can stand alone.