Unable is an adjective meaning not able — unable to attend. Enable is a verb meaning to make able, or to switch on — enable the setting. The prefixes do the work: un- negates, en- makes. The opposite of enable is disable, not unable.
The core difference
- unable — adjective: lacking the ability or means. I was unable to reach her, unable to pay.
- enable — verb: to give the ability or means; to switch a function on. The grant enabled them to expand, enable notifications.
The tell
Unable describes a person or thing and always pairs with to: unable to sleep. Enable has an object — someone or something is enabled — and a family: enabled, enabling, enabler. The switch-on sense has a clean opposite, disable; unable is never a verb and never a setting.
In use
- unable — I was unable to find the file. Unable to attend, she sent apologies.
- enable — The loan enabled them to expand. Enable two-factor login in settings.
Common slips
- I was enable to come → I was unable to come
- unable cookies in your browser → enable cookies in your browser
Unable is a state; enable is an action; disable undoes it.
Where the words come from
Both are able with a prefix, and able comes from Latin habilis, "handy, fit". Un- is the Old English negative; en- is the French causative prefix meaning "make", as in enlarge and enrich. Enable is recorded from the fifteenth century; the computing sense of turning a feature on dates from the twentieth.
Frequently asked questions
Is the opposite of enable unable?
No. The opposite of enable is disable. Unable is an adjective meaning not able.
Is it "I was unable to" or "I was enable to"?
Unable to. Enable is a verb and needs an object: "the software enables you to".
What is an enabler?
Someone or something that makes an action possible. In psychology it often means a person who makes another's harmful behaviour easier to continue.