Spelling & Vocabulary
Build your word power by learning about prefixes, suffixes, root words, and word families.
Root Words
A root word is the basic word before any prefixes or suffixes are added. It carries the core meaning. If you know the root, you can often work out the meaning of longer words.
Examples
play → player, playful, replay, playground
help → helpful, helpless, unhelpful, helper
happy → unhappy, happiness, happily
Tip: Finding the Root
Strip away any letters added to the beginning or end. What is left is usually the root word. For example, un-kind-ness → the root is kind.
Prefixes
A prefix is a group of letters added to the beginning of a root word to change its meaning. Learning common prefixes helps you understand and spell new words.
un- (means "not")
happy → unhappy, fair → unfair, kind → unkind
re- (means "again")
write → rewrite, do → redo, build → rebuild
dis- (means "not" or "opposite")
agree → disagree, appear → disappear, like → dislike
mis- (means "wrongly")
spell → misspell, lead → mislead, understand → misunderstand
"The prefix changes the meaning, but the spelling of the root word usually stays the same: un + happy = unhappy (not "unhapyy")."
Suffixes
A suffix is a group of letters added to the end of a root word. Suffixes can change the word's meaning or its word class (e.g. from a verb to a noun).
-ful (means "full of")
care → careful, colour → colourful, hope → hopeful
-less (means "without")
care → careless, hope → hopeless, use → useless
-ness (makes a noun)
kind → kindness, dark → darkness, sad → sadness
-ly (makes an adverb)
quick → quickly, slow → slowly, quiet → quietly
Watch Out: Spelling Changes
Sometimes the root word changes spelling when a suffix is added: happy + ness = happiness (y changes to i). hope + ful = hopeful (drop the e).
Word Families
A word family is a group of words that share the same root word. Knowing one word in the family helps you understand and spell the others.
Root: act
Root: form
Knowledge Check
Test your knowledge of prefixes, suffixes, root words, and word families.
Question 1
What is the root word in "unhappiness"?
Question 2
What does the prefix "re-" mean?
Question 3
Which word means "full of care"?
Question 4
What happens to the word "happy" when you add the suffix "-ness"?
Question 5
Which word belongs in the same word family as "instruct"?
Question 6
What does the prefix "dis-" do to a word?
Question 7
Which word is spelled correctly?
Question 8
The suffix "-less" means:
Question 9
Which word has both a prefix and a suffix?
Question 10
If "port" means "to carry", what does "transport" most likely mean?
Key Concepts Summary
- ●A root word is the base word before prefixes or suffixes are added.
- ●Prefixes (un-, re-, dis-, mis-) are added to the beginning and change the meaning.
- ●Suffixes (-ful, -less, -ness, -ly) are added to the end and can change meaning or word class.
- ●Word families share the same root word, helping you spell and understand related words.