HH.2 Determine the meanings of words with prefixes
What is a prefix?
A prefix is a word part added to the beginning of a base word. It changes the base word's meaning.
- Base word: happy
- Add prefix "un-": un + happy = unhappy
- The prefix "un-" changed "happy" to mean "not happy."
Think of a prefix as a helpful clue attached to the front of a word. It gives you a hint about the word's meaning before you even read the whole word.
How prefixes change meaning
Each prefix has its own meaning. When you attach it to a base word, it applies that meaning to the word.
- 1. Look for a prefix at the word's beginning.
- 2. Identify the base word that comes after it.
- 3. Combine the meaning of the prefix with the meaning of the base word.
Always check that the base word is a real word on its own. For example, in "redo," "do" is the base word.
Common prefixes and their meanings
These five prefixes are used frequently. Learning their meanings helps you understand many new words.
- re- means "again" → reread means "read again"
- un- means "not" or "opposite of" → unlock means "not locked" or "to open"
- dis- means "not" or "opposite of" → disagree means "not agree"
- pre- means "before" → preview means "view before"
- mis- means "wrongly" → misplace means "to place wrongly"
Both un- and dis- can mean "not," but they are used with different base words. You will learn which to use by practicing.
Using prefixes in sentences
Understanding prefixes helps you determine the meanings of words when you read and allows you to use more precise words when you write.
- re-: Please rewrite your sentence neatly. (write again)
- un-: My shoelace became untied. (not tied)
- dis-: It is impolite to disrespect others. (show a lack of respect)
- pre-: We ate a prepackaged snack. (packaged before)
- mis-: I did not mean to mislead you. (lead in the wrong direction)
When you see a new word with a familiar prefix, try the prefix's meaning first. If "preheat" means "heat before," what might "prepay" mean?