Suffix Words
A suffix is a word part added to the end of a base word: -ful means full of (helpful), -less means without (hopeless), -er and -est compare things (faster, fastest), and -ness turns a describing word into a naming word (kind becomes kindness).
Unlike prefixes, suffixes can change the spelling of the base word, which is why they get their own set of rules. Big becomes bigger with a doubled g, while fast becomes faster with no change at all - and knowing why is the whole game.
The list below comes from our Grade 3 spelling curriculum and mixes all five suffixes so students practice choosing the right rule, with printables and free online practice for every word.
The rule
A suffix attaches to the end of a base word: help + ful = helpful, hope + less = hopeless, big + er = bigger, kind + ness = kindness. Suffixes starting with a vowel can trigger spelling changes in the base (big doubles its g); suffixes starting with a consonant usually leave the base alone.
Suffix Words by grade, from our curriculum
These are the exact lists our K-6 spelling curriculum teaches. Every list links to free online practice and printable worksheets - no account needed.
Common Suffixes (-ful, -less, -er, -est, -ness)
Grade 3- helpful
- hopeless
- bigger
- biggest
- kindness
- careful
- careless
- faster
- fastest
- darkness
How the pattern works
The doubling rule (teachers call it 1-1-1): a one-syllable word with one short vowel and one final consonant doubles that consonant before a suffix that starts with a vowel. That is why big becomes bigger and biggest. Fast ends in two consonants, so it just takes -er and -est unchanged. One exception: x never doubles, so mix becomes mixer.
Suffixes that start with a consonant (-ful, -less, -ness) simply attach when the base ends in a consonant or silent e: hope + less = hopeless, care + ful = careful, dark + ness = darkness. The silent e in hope and care stays, because nothing vowel-shaped arrives to replace it. (A base ending in y changes it to i first: happy, happiness - a rule for a later list.)
The suffix -ful always has one l, even though it comes from the word full: helpful, careful. And -er does double duty in English: it compares (faster) and it names a person who does something (teacher, farmer) - same spelling, two jobs.
Common mistakes to watch for
- Writing -full instead of -ful ("helpfull", "carefull") - the suffix dropped one l centuries ago and never took it back.
- Forgetting to double ("biger" for bigger) or doubling where nothing is needed ("fastter") - the 1-1-1 rule decides, and fast fails the one-final-consonant test.
- Dropping the base word's silent e before a consonant suffix ("hopless" for hopeless, "carless" for careless) - the e stays because -less and -ful start with consonants.
- Spelling the sound instead of the suffix ("darknes", "kindniss") - -ness is always n-e-s-s, a fixed unit worth teaching as one chunk.
Example sentences
- helpful - The map was helpful on the first day of camp.
- careless - One careless splash soaked the whole painting.
- bigger - Their pumpkin grew bigger than the wheelbarrow.
- fastest - She ran the fastest lap of the afternoon.
- kindness - A small kindness can change someone's whole day.
Taught in Grade 3 in our curriculum, after prefixes. The suffix rules (doubling, silent e, one-l -ful) carry students through thousands of words, so this list gets revisited until the choices are automatic.
Frequently asked questions
What is a suffix?
A word part added to the end of a base word: -ful (full of), -less (without), -er and -est (comparing), -ness (a state or quality). Helpful, hopeless, bigger, biggest, kindness.
Why does bigger have two g letters but faster only one t?
The 1-1-1 doubling rule: one syllable, one short vowel, one final consonant means the consonant doubles before a vowel suffix. Big qualifies; fast ends in two consonants, so it does not.
Why is -ful spelled with one l?
The suffix came from the word full but settled on a single l centuries ago: helpful, careful, wonderful. Only the standalone word full keeps both.
What does -ness do to a word?
It turns a describing word into a naming word: kind becomes kindness, dark becomes darkness. The spelling of the suffix never changes, so it can be taught as one fixed chunk.
Turn these lists into practice in one click
Free spelling games, tests, and printables for every list above - built for K-6 classrooms and home practice. No signup, no cost.