Glossary · Word parts and vocabulary
What is a prefix?
Definition
A prefix is a part attached to the front of a word that changes its meaning, such as un- in unhappy or re- in rebuild.
Prefixes change meaning but rarely change spelling. Un- plus happy is unhappy; dis- plus agree is disagree. The base stays the same, which makes prefixes easier to spell than suffixes.
A small set covers most prefixed words students meet. Un-, re-, in- (and im-, il-, ir-), and dis- account for a large share of them. Teaching those four early pays off quickly.
Watch for false prefixes. The re in ready and the un in uncle aren't prefixes, because what's left isn't a word part. A quick check helps: remove the supposed prefix and see whether a meaningful base is left.
In a lesson
Write unlock, refill and dislike. The student circles each prefix and says what the word means. Then try uncle: remove un and what's left isn't a word, so un isn't a prefix there.
Examples
Each word with its spelling units, one per sound.
- unhappyu·n·h·a·pp·y
- unknownu·n·kn·ow·n
- unclearu·n·c·l·ear
- replayr·e·p·l·ay
- disagreed·i·s·a·g·r·ee
- misusem·i·s·u_e·s
Words come from our lexicon, checked against a pronouncing dictionary. Words a student sees in our assessments are left out.
Why does this matter for the record?
Track prefix meanings in a list. Spelling with prefixes is rarely the problem; knowing what they mean is.
Rate each skill as you teach it
Needs support, Developing, Secure. The rating schedules the review and builds the report.