A suffix at the end of a word often tells you what kind of word it is. These four endings make adjectives, words that describe: famous, active, readable, heroic.
Key idea
-ous (also -ious, -uous) = full of, having. -ive = tending to, doing. -ible, -able = able to be, worth being. -ic, -ical = having to do with, like.
The ending tells you the word’s job; the root tells you its meaning. Put them together: timorous is timor (fear) + -ous (full of), full of fear. malleable is malle (hammer) + -able: able to be hammered into shape. cryptic is crypt (hidden) + -ic: having to do with hidden things.
The parts and their words
Words taken apart
| Word and meaning | Parts, and what they say |
|---|---|
| copious plentiful | copi plenty + -ous full of → “full of plenty” |
| timorous fearful and nervous | timor fear + -ous full of → “full of fear” |
| credible believable; worthy of trust | cred believe + -ible able to be → “able to be believed” |
| malleable easily shaped; also, easily influenced | malle hammer + -able able to be → “able to be hammered (into shape)” |
| pensive deeply thoughtful, often sadly | pens weigh + -ive tending to → “tending to weigh (thoughts)” |
| evasive avoiding a direct answer | e- out + vas go + -ive tending to → “tending to slip out” |
| cryptic mysterious and hard to understand | crypt hidden + -ic having to do with → “having to do with hidden things” |
| chronic lasting a long time or coming back again and again | chron time + -ic having to do with → “having to do with (long) time” |
Worked example: Let the ending do the work
Fill the blank with the right form: “The witness gave a ______ account of the accident.” Choices: credit, credence, credible, credibly.
- The blank comes between a and the noun account, so it needs an adjective.
- -ible makes adjectives: credible, “able to be believed.”
- credit and credence are nouns; credibly is an adverb.
Answer: credible
Meet the word
Common mistake
Expecting the ending to tell you the meaning. It tells you the part of speech, not what the word means: copious (plentiful), pernicious (harmful) and impetuous (rash) are all adjectives in -ous, but they mean very different things. Use the root for the meaning.