Word Confusion: Ability vs Capability vs Capacity

Posted November 5, 2015 by Kathy Davie in Author Resources, Editing, Self-Editing, Word Confusions, Writing

Ability, capability, and capacity all revolve around a central premise of power, skill, or production of an action. It’s a good part of the reason why it’s so easy to experience word confusion.


Ability is “the quality or state of being able” to perform physically, mentally, or legally in a particular area. The skill may be natural or acquired and either mental or physical. The person, animal, or object is already able to perform.


Capability is the “quality or state of being capable”, of having the potential that can be developed.


Capacity primarily relates to the measure of a container’s ability to hold volume or quantities. A more general interpretation is the native potential to develop a mental skill. It’s not a characteristic that can be acquired or developed.

Consider the Following

I have the ability to write.

I’ve always been interested in writing, and I took some classes.

I don’t have the capability to write a novel.

My skill is in poetry, not creating a fictional story.

As an able writer, I do have the capacity to write a novel, but I don’t want to.

I don’t want to put the mental effort into writing a long story.

Her computer has an Ethernet port so it has the ability to access the Internet.

It has a network card, and someone has to connect it to a modem with a CAT-5 cable.

She made sure her computer had no online capabilities so no one could ever hack into it.

No one would ever be able to hook the computer up to the Internet as it had no network card.

Her home network has the capacity to support one laptop, one cell phone, and an iPad. If she wants to add a wireless printer, she’s out of luck.

Her modem can only handle so many wireless devices.

You don’t have the ability to care.

He never even took a CPR class and hasn’t the first clue about first aid.

You don’t have the capability to care.

She faints at the sight of blood.

You don’t have the capacity to care.

He’s a psychopath with no room for human kindness.

Word Confusions started as my way of dealing with a professional frustration with properly spelled words that were out of context in manuscripts I was editing as well as books I was reviewing. It evolved into a sharing of information with y’all. I’m hoping you’ll share with us words that have been a bête noir for you from either end. Consider sharing this Word Confusion with friends by tweeting it.

Ability Capability Capacity
Credit to: Apple Dictionary.com; Merriam-Webster: capability and capacity; Dictionary.com: capability and capacity

An underwater explosion in the ocean next to an aircraft carrier.

Image by PH2 Norr, U.S. Navy, is in the public domain, via Wikimedia Commons

A test blast is conducted USS Theodore Roosevelt‘s ability to withstand underwater shock waves.

An overview of the Blenheim Palace park designed by Capability Brown

Image by Nicolas Vergnaud [CC0], via Wikimedia Commons

Ya gotta admit “Capability” Brown had quite the capability for designing natural-looking parks.

Overfilling a crystal glass of crystal clear water

Image courtesy of Cure Zone

I reckon this glass has overflowed its capacity.

Part of Grammar:
Noun 1
Noun plural: abilities
Suffix 2
Noun plural: capabilities
Adjective 3; Noun 4
Noun plural: capacities
[Noun singular, with infinitive] Possession of the means or skill to do something

Talent, skill, or proficiency in a particular area

Natural aptitude

Acquired proficiency

Forming nouns of quality corresponding to adjectives ending in -able

Quality or state of being capable

Power or ability to do something

  • [Often capabilities] The extent of someone’s or something’s ability
  • A feature or faculty capable of development
  • A facility on a computer for performing a specified task
  • Forces or resources giving a country or state the ability to undertake a particular kind of military action

Ability to undergo or be affected by a given treatment or action

Qualities, abilities, features, etc., that can be used or developed

Reaching maximum capacity

[Noun singular] The maximum amount that something can contain

  • [As modifier] Fully occupying the available area or space
  • The amount that something can produce
  • The total cylinder volume that is swept by the pistons in an internal combustion engine
  • Former term for capacitance

[Medicine] The measure of potential cubic contents of a capacity or receptacle

  • Volume

The ability or power to do, produce, experience, or understand something

[Noun singular] A specified role or position

The manager had lost his ability to motivate the players.

account accountability

address addressability

applicable applicability

capable capability

inadvisable inadvisability

marketable marketability

persuade persuadability

suitable suitability

supportable supportability

He had an intuitive capability of bringing the best out in people.

This innovation has the capability to increase productivity.

The job is beyond my capabilities.

The graphics card gives this computer a tremendous graphics capability.

Do not underestimate their nuclear weapons capability.

It has the capability to replace twenty men.

As a group we have the capability of accomplishing more than as a single individual.

I love that my DVR has the capability to record two programs at once.

Though dilapidated, the house has great capabilities.

It gives the glass the capability of resisting high heat.

It was a capacity audience.

The show attracted a capacity crowd.

The capacity of the freezer is 1.1 cubic feet.

The stadium’s seating capacity.

The room was filled to capacity.

They played to a capacity crowd.

The company aimed to double its electricity-generating capacity.

When running at full capacity, the factory will employ 450 people.

I was impressed by her capacity for hard work.

His capacity to inspire trust in others is mind blowing.

Their intellectual capacities have begun to fill.

In cases where a patient’s testamentary capacity is in doubt, a court-appointed psychiatrist will assess their capability.

I was engaged in a voluntary capacity.

Writing in his capacity as legal correspondent, he used a lot of five-dollar words.

The total capacity of a channel may be shared between several independent data streams using some kind of multiplexing.

Adjective: able
Noun: subability, subabilities
Adjective: capable, incapable
Adverb: capably, incapably
Noun: capableness, incapableness, incapability, overcapability, overcapabilities, supercability, supercabilities
Adjective: capacitative, capacitive
History of the Word:
1 Late Middle English from the Old French ablete, from the Latin habilitas, from habilis meaning able.

2 From French -abilité or Latin -abilitas, noun endings.

First known use: 1587

From the Middle French capabilité, from the Late Latin capābili (capable + -ty).

3 First known use: 1897

4 Late Middle English from the Middle French capacité, from Latin capacitas, which is from capax, capac- meaning that can contain, from capere (take or hold).

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C’mon, get it out of your system, bitch, whine, moan…which words are your pet peeves?

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