What this suffix does
-founded evaluates how solid the basis of a claim or fear is: well-founded, ill-founded. "a well-founded fear" = a justified fear.
ESEN
Suffix · forms adjectives
-founded
Judges how solid the basis of a claim or fear is: well-founded (justified, based on good evidence) versus ill-founded (baseless).
In Spanish: fundamentado / fundado / con baseIntermediate
Written by Bryan López, English teacher · Updated
How it is formed
Adverb + founded.
- well + foundedwell-founded (justified)
- ill + foundedill-founded (baseless)
- poorly + foundedpoorly-founded (weakly supported)
This is not a productive rule you can apply freely: it is a closed set of fixed expressions. Learn them one by one as set phrases.
How it is pronounced
-founded
Tap the button to hear how the ending sounds. Each word in the table has its own audio.
Examples
Base word
With -founded
In a phrase
- wellwell-foundedHer worries about the project turned out to be well-founded.
- illill-foundedHis complaint was ill-founded, there was no real problem.
- soundlysoundly-foundedThe report is soundly-founded on years of research.
- firmlyfirmly-foundedTheir friendship is firmly-founded on years of trust.
- poorlypoorly-foundedThe rumor was poorly-founded and turned out to be false.
Common mistakes
well-founded = well-known or well-established by time alone
well-founded = based on strong evidence or sound reasoning, regardless of how old it is
"Well-founded" is an epistemic judgment, not a temporal one. A new concern can be well-founded if the evidence is strong; an ancient belief can be ill-founded if the evidence was always weak. The compound evaluates the quality of the foundation, not its age or familiarity.
unfounded and ill-founded mean the same thing
unfounded = having no foundation at all; ill-founded = having a weak or inadequate foundation
"Unfounded" means having no basis at all — a pure invention or baseless assertion. "Ill-founded" implies that there is some kind of foundation, but it is inadequate, weak, or flawed. An ill-founded concern might have some evidence behind it but not enough to justify the level of concern. An unfounded claim has no evidence at all.
A trick to remember it
well-founded = "solidly based", from "found" (to base something solidly, not "to start a company"). Think of a building's foundation: well-founded = with a solid foundation.
Practise what you learned
Exercise 1 · Form the word
Exercise 2 · Pick the right one
"a well-founded concern" is a worry that is...
Frequently asked questions
What does the suffix -founded mean in English?
The suffix -founded judges how solid the basis of a claim or fear is: well-founded (justified, based on good evidence) versus ill-founded (baseless). In Spanish it usually maps to fundamentado / fundado / con base.
Can you give an example of a word with -founded?
"well" becomes "well-founded". It is a typical example of the -founded suffix.
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