Teaching prefixes
Aim: Add prefixes to root words and keep both parts spelled in full.
How to explain it
A prefix goes on the front of a word to change its meaning, and the word behind it never changes. So when the prefix ends with the same letter the word starts with, both letters stay: mis + spell = misspell, un + necessary = unnecessary. When they are different, there is no double: dis + appear = disappear. The prefix in- changes to im- before b, m or p (impossible), to il- before l (illegal) and to ir- before r (irregular).
Starter (5 minutes)
Show root words on one side of the board and prefixes on the other. Children join them and read the new word aloud, saying what the prefix did to the meaning.
Main activity
Word sums with a twist: give pairs that make a double letter (mis + spell, dis + satisfied, un + natural) mixed with pairs that don't (dis + appear, mis + take). Children write each word and circle any double letter, explaining where each letter came from.
Dictation sentences
- It is impossible to disagree with you.
- Please don't misspell your own name.
- The magician made the rabbit disappear.
Watch out for
- Adding an extra letter where there is no double (dissappear).
- Dropping a letter where there is one (mispell, unecessary).
- Using in- where im-, il- or ir- is needed (inpossible).
Quick check
Ask children to spell these without help:
- unnecessary
- misspell
- disappear
- irregular
Example words
- unhappy
- undo
- disagree
- disappear
- misbehave
- misspell
- redo
- preview
- impossible
- irregular
- illegal
- incorrect