Changing Word Meanings with the Prefixes Un and Re
About this lesson
Children add the prefixes un- and re- to familiar base words, work out what each new word means, and use it in a spoken sentence. They practise breaking words into parts to figure out meaning. You need only a whiteboard and scrap paper, and it takes about 12 minutes.
- Grade
- 3
- Subject
- ELA
- Time
- 12 min
- Prep
- 3 min
Objective
Students will add the prefixes un- (not, or the opposite of) and re- (again) to base words and correctly explain how the prefix changes each word's meaning.
Prep
3 min: write two column headings, un- = not / opposite and re- = again, and these 10 base words on the board: happy, tie, lock, fill, kind, paint, read, pack, fair, build
Materials
- whiteboard and marker
- scrap paper
- pencils
Steps
- Point to the headings and say, "A prefix is a word part added to the front of a word to change its meaning. Un- means not or the opposite, and re- means again." Model one of each: un + happy = unhappy (not happy), re + paint = repaint (paint again).
- Put students in pairs and have them copy the two headings onto scrap paper. Each pair adds a prefix to every remaining base word and writes it in the matching column, trying both prefixes to see which makes a real word.
- After about 4 minutes, call on pairs to come up and write one word in the correct column on the board. Each pair says the new word's meaning using the pattern "___ means ___."
- Point to three of the new words and ask each pair to whisper a sentence using one of them to their partner. Then invite a few pairs to share their sentences with the class.
- Finish by asking, "Which base words worked with both prefixes?" Answers include tie, lock, pack, fill and build. Discuss how untie and retie mean different things.
Quick Check
Say a new word such as "unsafe" or "rewrite". Students show one finger for not/opposite or two fingers for again, and one student explains the meaning.
Differentiation
Make it easier: Use only un- with five base words, and act out each meaning together (for example, lock and unlock with a pretend key).
Make it harder: Add the prefix dis- (dislike, disagree, disappear) and challenge pairs to write a short three-sentence story using at least three prefixed words.
Good For
- Before lunch
- Supply teacher
- Review
- End of day
