Suffix · forms adjectives
Turns a noun into an adjective meaning "full of" or "having": care becomes careful.
Written by Bryan López, English teacher · Updated
The suffix -ful takes a noun and turns it into an adjective meaning "full of" or "having a lot of". From "care" you get "careful" (full of care); from "help" you get "helpful"; from "power" you get "powerful". The clue is in its origin: -ful comes from "full". careful = full of care. If you think "full of [noun]", you will almost always get the meaning right.
This is the number-one mistake with -ful. Even though it comes from "full" (two Ls), the SUFFIX -ful is ALWAYS written with a single L. careful ✓ carefull ✗ useful ✓ usefull ✗ beautiful ✓ beautifull ✗ Lock it in: the word "full" has two Ls, but as a suffix it drops one. One L, every time.
-ful has a twin that means the opposite: -less ("without"). They form perfect pairs worth learning together: careful ↔ careless useful ↔ useless hopeful ↔ hopeless Learning -ful and -less at the same time gives you two adjectives for every noun.
The rule is simple: noun + ful (a single L). Just mind a final -y.
When the noun ends in -y, that -y becomes -i before -ful: beauty → beauti + ful → beautiful. And remember: always a single l. For the adverb, add -ly to the adjective: careful → carefully.
-ful/fəl/ · soft 'ful', with ONE l
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The suffix -ful has a single l, even though it comes from "full" (two Ls). Same for useful, helpful, beautiful.
When the noun ends in -y, that -y becomes -i: beauty → beautiful.
careful is an adjective (it describes a person or thing). To describe a VERB you need the adverb: careful → carefully.
A trick to remember it
Link -ful with "full": careful = full of care. And the golden spelling rule: "full" has two Ls, but the suffix -ful drops one. A single l, always.
Exercise 1 · Form the word
Exercise 2 · Pick the right one
Which spelling is correct?
Exercise 3 · Pick the right one
"beauty" becomes an adjective as…
The suffix -ful turns a noun into an adjective meaning "full of" or "having": care becomes careful. In Spanish it usually maps to -oso.
The ending -ful is pronounced /fəl/ · soft 'ful', with ONE l. For example, "careful".
"care" becomes "careful". It is a typical example of the -ful suffix.
-tion, -ness, -ful, -ly, -able... every ending you need to understand thousands of words at once.