Roots, Prefixes & Suffixes — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
The student was displeased with her grade, so she celebrated happily.
Corrected: The student was displeased with her grade, so she asked the teacher how to improve.
The prefix dis- means "not" or "opposite," so displeased means unhappy. Someone who is unhappy with a grade would ask how to improve, not celebrate happily.
2. Fix the sentence:
The nonfiction book told an imaginary story about a dragon and a wizard.
Corrected: The nonfiction book told a true story based on real events and facts.
The prefix non- means "not," so nonfiction means "not fiction" — it covers real events and facts, not imaginary stories about dragons and wizards.
3. Fix the sentence:
He overslept and arrived at school thirty minutes early.
Corrected: He overslept and arrived at school thirty minutes late.
The prefix over- means "too much," so oversleeping means sleeping too long. That extra sleep would make someone arrive late, not early.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. The prefix un- means "not," so if something is unclear, it is not clear.
The prefix un- means "not," so removing un- from "unclear" leaves "clear" — something unclear is simply not clear.
2. Adding the prefix dis- to "agree" creates disagree, which means to have a different opinion.
The prefix dis- means "not" or "opposite of," so dis- plus "agree" creates "disagree," meaning to hold an opposing opinion.
3. A nonsmoking area in an airport is a section where smoking is not allowed, because non- means not.
The prefix non- means "not," so a nonsmoking area is one where smoking is not permitted — non- reverses the meaning of the base word.
4. The prefix over- means "too much," so to overwater a plant means to give it too much water.
Since over- means "too much," overwater means giving a plant more water than it needs, which can drown its roots.
Part C: Short Answer
Answer each question in one or two complete sentences.
1. Explain what the prefix dis- means and give two words that use it. Tell what each word means.
Sample answer: The prefix dis- means "not" or "the opposite of." The word disconnect means to separate something that was joined. The word dishonest means not honest or truthful.
Dis- means "not" or "the opposite of," so it flips a word's meaning. Disconnect means to undo a connection, and dishonest means the opposite of honest — not truthful.
2. How are the prefixes un- and non- alike? How can knowing them help you figure out new words? Give an example.
Sample answer: Both un- and non- mean "not." If I see the word "nonessential," I know it means not essential or not required, even if I have never seen the word before.
Both un- and non- mean "not," so recognizing either prefix lets you decode unfamiliar words. For example, "nonessential" must mean "not essential" even if you have never seen the word before.