Second Grade English: Prefixes (un-, re-, dis-, pre-)
In the architecture of English words, special letter combinations can be attached to the very front of a base word to alter its meaning. These front-attached word parts are called prefixes. The term prefix itself begins with the prefix pre-, which means "before!" By attaching a small prefix of just two, three, or four letters, you can flip a word into its exact opposite, describe an action happening again, or show that something is occurring beforehand. In this chapter, you will master four of the most powerful and common prefixes in second grade: un-, re-, dis-, and pre-.
How Prefixes Change Word Meanings
A prefix is an affix placed before the stem of a word. A prefix cannot stand alone as an independent word, but it carries a consistent, defined meaning that transforms whatever base word it touches.
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| THE PREFIX ATTACHMENT FORMULA |
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| |
| [ PREFIX ] + [ BASE WORD ] = [ NEW WORD ] |
| |
| re- (again) + write (base) = rewrite |
| (to write again!) |
| |
| un- (not) + lock (base) = unlock |
| (to undo lock!) |
| |
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The No-Spelling-Change Rule for Prefixes
One of the most wonderful things about prefixes is that they are incredibly easy to spell. Unlike suffixes, which often require you to drop an 'e' or double a consonant, prefixes almost never change the spelling of the base word! You simply glue the prefix directly onto the front of the base word without dropping or adding any letters.
The Four Master Prefixes of Second Grade
Let us inspect each of our four target prefixes, discovering their core meanings and observing how they transform everyday words.
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| MASTER PREFIX DIRECTORY |
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| Prefix | Core Meaning | Examples |
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| un- | not; opposite of; | unhappy, unlock, unsafe, |
| | undo an action | untie, unpack, untrue |
| re- | again; back | reread, rewrite, replay, |
| | | return, refill, remake |
| dis- | not; opposite of; | dislike, disagree, disappear, |
| | away from | disobey, distrust, disorder |
| pre- | before; in advance | preschool, preheat, preview, |
| | | prepay, pretest, predict |
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The Prefix un-: The Great Reverser
The prefix un- has two primary superpowers: First, it means "not." If someone is unhappy, they are not happy. If a bridge is unsafe, it is not safe. Second, it reverses an action. If you tie your sneakers, untie means to reverse the knot. If you pack a suitcase, unpack means to take everything out.
The Prefix re-: Doing It Once More
The prefix re- means "again" or "back." If you reread a chapter, you read it again to understand it better. If you refill your water glass, you fill it again. If you return a library book, you bring it back to its original place.
The Prefix dis-: The Opposing Force
The prefix dis- means "not" or "opposite of," often carrying a sense of separation or disagreement. If you dislike broccoli, you do not like it. If two friends disagree, they do not agree. If a magician makes a coin disappear, it goes away from sight.
The Prefix pre-: Doing It Ahead of Time
The prefix pre- means "before." If you preheat an oven before baking cookies, you heat it in advance. If you attend preschool, you go to school before elementary school begins. If you watch a movie preview, you see scenes before the movie is released.
Prefix Detective: Avoiding the False Prefix Trap
Just because a word starts with the letters re or un does not automatically mean it contains a prefix! You must always verify that what remains after removing the letters is a genuine base word.
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| REAL PREFIX VS. FALSE PREFIX CHECK |
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| Word | Remove Prefix Letters | Is Remaining Word Real? |
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| replay | re- + play | YES! "play" is a real word. |
| ready | re- + ady | NO! "ady" is nonsense. |
| unlock | un- + lock | YES! "lock" is a real word. |
| under | un- + der | NO! "der" is nonsense. |
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Practice Exercises
Exercise 1: Add the correct prefix (un-, re-, dis-, or pre-) to match each definition: to heat an oven before baking; not happy; to read a book again; to not agree with someone.
Exercise 2: Read the sentence: "Before the game, Leo had to preheat the pizza, unlock the back door, and replay the coach's video message." Identify the three words that contain prefixes and state their base words.
Exercise Solutions
Solution to Exercise 1: To heat an oven before baking is preheat (prefix pre-). Not happy is unhappy (prefix un-). To read a book again is reread (prefix re-). To not agree with someone is disagree (prefix dis-).
Solution to Exercise 2: The three words containing prefixes are preheat (base word heat), unlock (base word lock), and replay (base word play).