Prefixes
Guidelines:
A prefix is a group of letters that appears at the front of a word. A
prefix affects the meaning of the root (base) word to which it is attached.
To determine whether or not a group of letters is a prefix, remove them
from the word. The letters are a prefix if a known word remains. For example, remove the letters un from the following words: unhappy, untie, uncle,
uninterested. In which word are the letters un not a prefix? Yes, these letters are not a prefix in the word uncle.
Make students aware of the following warnings about prefixes.
1. Most prefixes have more than one meaning.
For example, the prefix un can mean “not” as in
unhappy, or “do the opposite of” as in untie.
Teach the multiple meanings of the most common prefixes, and use careful language during
lessons such as, “the prefix un sometimes
means not.”
2. Be careful of letter clusters that look like prefixes, but aren’t. For example, when the letters
un are removed from uncle, no recognizable root
word is left. In addition, when the letters in are
removed from invented, the word that remains
has no relation to the whole word. The prefixes
that cause the most difficulty are re, in, and dis.
3. Don’t rely solely on word-part clues to determine meaning. Use context clues as well to verify a word’s meaning. For example, you might
think the word unassuming means “not assuming/not supposing” instead of its actual meaning
“modest.” It is estimated that about 15 to 20% of the prefixed words students will encounter share this complexity (White et al., 1989).
Teach only the most common prefixes. The chart that follows shows
the most common based on a count of prefixed words appearing in the
Word Frequency Book (Carroll, Davies, and Richman, 1971). The prefix un
alone accounts for almost one-third of the total. The top three on the list
account for over half.