Prefixes are groups of letters added to the beginning of a word to change its meaning. They are an important part of English grammar and vocabulary because they help you form new words and understand more complex meanings.
- A prefix is always added to the start of a base word.
- Prefixes do not change the part of speech of the base word.
- Prefixes can create opposites or change the meaning in other ways.
- Knowing common prefixes can help you guess the meaning of new words.
What Are Prefixes?
Prefixes are fixed parts added to the beginning of a word to change its meaning.
- A prefix cannot stand alone; it must be attached to a base word.
- The base word remains a real English word.
- Prefixes usually do not change the word’s part of speech.
- Prefixes give clues about the meaning of the new word.
If a prefix is added to the word "happy" to mean "not happy," what is the new word?
unhappy
The prefix "un-" means "not" or "opposite," so adding it to "happy" creates "unhappy," meaning "not happy."
Common English Prefixes
Here are some of the most common English prefixes, their meanings, and example words.
| Prefix | Meaning | Example | New Word Meaning |
|---|---|---|---|
| un- | not, opposite | happy → unhappy | not happy |
| re- | again, back | write → rewrite | write again |
| pre- | before | view → preview | see before |
| mis- | wrongly | spell → misspell | spell wrongly |
| dis- | not, opposite | agree → disagree | not agree |
| over- | too much | cook → overcook | cook too much |
| under- | too little | paid → underpaid | paid too little |
| non- | not | fiction → nonfiction | not fiction |
| in- / im- | not, into | correct → incorrect, | not correct; impossible |
| sub- | under | way → subway | under the way |
| inter- | between | nation → international | between nations |
| super- | above, beyond | human → superhuman | above human |
| anti- | against | virus → antivirus | against virus |
| auto- | self | graph → autograph | self writing |
| ex- | former | president → ex-president | former president |
How to Use Prefixes
Follow these steps to use prefixes correctly.
- Identify the base word.
- Choose the appropriate prefix based on the meaning you want.
- Attach the prefix directly to the beginning of the base word (no space or hyphen).
- Check the spelling (usually no change is needed).
- Use the new word in context.
Examples
Here are some example sentences to show how prefixes change meanings.
| Base Word | With Prefix | New Meaning | Example Sentence |
|---|---|---|---|
| happy | unhappy | not happy | She is unhappy with her grade. |
| do | redo | do again | I need to redo my homework. |
| taste | untaste | no common use* | - |
| lock | unlock | opposite of lock | Can you unlock the door? |
| possible | impossible | not possible | It’s impossible to finish today. |
Translate the sentence: 'Can you unlock the door?'
Can you open the door?
"Unlock" means "open" or "remove the lock," formed by adding the prefix "un-" to "lock."
Tips for Learners
- Start by learning the most common prefixes.
- Use context clues to guess the meaning of words with prefixes.
- Practice by creating your own sentences.
- Remember that some prefixes have more than one meaning.
- Not all prefixes form common words (e.g., untaste is not used).
Prefixes are a powerful tool to expand your English vocabulary and improve reading and writing skills.
Last updated: Wed Jun 18, 2025
