Quick answer: Use ability for a skill you have and can demonstrate now: She has the ability to solve problems quickly. Use capability for potential or maximum capacity — what someone or something could do: The new server has the capability to handle a million requests. When in doubt: ABILITY = current, demonstrated skill; CAPABILITY = potential, possible capacity. For a fuller definition, see the Cambridge Dictionary entry for ‘ability’.
Comparison Table
| Word | Part of Speech | Meaning | Example |
|---|---|---|---|
| ability | noun | a current, demonstrated skill or power to do something | He has the ability to speak four languages. |
| capability | noun | the potential or capacity to do something, whether or not it is used yet | The factory has the capability to double output. |
Using Ability
Ability refers to a skill or quality that a person already has and can put into practice. It is something demonstrable and usually personal — tied to talent, training, or natural aptitude. When you describe what someone can actually do right now, ability is the natural choice.
She showed great ability in mathematics from an early age.
His ability to stay calm under pressure impressed the panel.
The team lacked the ability to defend against fast attacks.
Reading widely improves your ability to write clearly.
Notice that each example describes a skill that is present and observable. We use ability when the skill is already there, not merely possible.
Ability with To-Infinitive
Ability is very often followed by to + verb: the ability to learn, the ability to adapt, the ability to concentrate. This structure is one of the most reliable ways to spot that ability is the right word.
Babies have a remarkable ability to absorb new sounds.
Good leaders have the ability to listen.
Using Capability
Capability emphasises potential, capacity, or the maximum that someone or something is able to achieve — sometimes whether or not that potential has been used. It is common in technical, military, business, and engineering contexts, and frequently appears in the plural (capabilities).
The aircraft has long-range capability.
We are expanding our manufacturing capability.
The software’s reporting capabilities are impressive.
She has the capability to lead the whole department one day.
Capability in Technical and Business English
In professional contexts, capability describes what a system, organisation, or product is built to do: storage capability, defensive capability, analytical capabilities, nuclear capability. It points to capacity and scope rather than a personal, demonstrated talent.
Key Differences at a Glance
- Time: Ability describes a present, demonstrated skill; capability often points to potential or future capacity.
- Focus: Ability is about what one can do; capability is about how much one could do or the scope of what is possible.
- Context: Ability is personal and everyday; capability is common in technical, military, and business writing.
- Plural: Capabilities is widely used for the range of features a system offers; abilities usually refers to a person’s skills.
Side-by-Side Examples
He has the ability to fix the engine. (he can do it now)
The garage has the capability to service electric vehicles. (it has the capacity/equipment)
Her ability to negotiate saved the deal.
The firm’s capability to scale globally attracted investors.
Common Mistakes
✗ She has the capability to play the violin beautifully.
✓ She has the ability to play the violin beautifully.
✗ The data centre has the ability to store ten petabytes.
✓ The data centre has the capability to store ten petabytes.
✗ The tool offers powerful abilities for analysis.
✓ The tool offers powerful capabilities for analysis.
Memory Tip
Think of ABILITY = ABLE now — a skill you are able to use today. Think of CAPABILITY = CAPACITY — both start with CAP and point to potential, scope, and how much could be done.
Ability or Capability?
Four questions — choose the correct word for each sentence.
1. “She has the ___ to solve problems quickly.” (a skill she already has)
2. “The new server has the ___ to handle a million requests.” (potential capacity)
3. “He has the ___ to speak four languages.”
4. “The factory has the ___ to double output.” (not doing it yet, just possible)
Frequently Asked Questions
What is the main difference between ability and capability?
Ability is a current, demonstrated skill — what a person can actually do now. Capability is potential or maximum capacity — what someone or something could do, whether or not that potential is currently used. Ability is personal and immediate; capability points to scope and possibility.
Can ability and capability be used interchangeably?
Sometimes, but they carry different nuances. “She has the ability to lead” means she can lead now. “She has the capability to lead” suggests she has the potential to lead, perhaps in the future. For demonstrated personal skills, ability is safer; for potential and system capacity, capability fits better.
Which word is used more in business and technology?
Capability is far more common in business, engineering, military, and technology contexts. We speak of a product’s capabilities, a company’s manufacturing capability, or a system’s processing capability. Ability tends to describe individual people rather than systems or organisations.
What are common collocations with ability?
Common collocations: the ability to learn, natural ability, athletic ability, the ability to adapt, problem-solving ability, mental ability, the ability to concentrate, exceptional ability. Ability is very often followed by “to” plus a verb.
What are common collocations with capability?
Common collocations: technical capability, manufacturing capability, defensive capability, processing capability, the capability to expand, military capability, analytical capabilities, storage capability. Capability often appears in the plural, “capabilities,” especially for products and systems.
Is capability more formal than ability?
Capability tends to sound more formal and technical, which is why it appears so often in business and engineering writing. Ability is more everyday and personal. In casual conversation, ability is far more common; capability is reserved for capacity, potential, and systems.
Can a person have capability rather than ability?
Yes. Saying a person has the capability to do something stresses untapped potential — they could do it, perhaps with training or in the right conditions. Saying they have the ability stresses a skill they already possess and can demonstrate now.
What is the adjective form of ability and capability?
The adjective linked to ability is “able”: an able student. The adjective linked to capability is “capable”: a capable engineer. Both adjectives are followed by “of” or “to”: capable of leading, able to lead.
Do ability and capability have plural forms?
Yes. Abilities usually refers to a person’s various skills: “her musical abilities.” Capabilities usually refers to the range of features a system, product, or organisation offers: “the software’s reporting capabilities.”
How do ability and capability appear in IELTS writing?
Use ability when writing about personal skills: “Technology improves students’ ability to research.” Use capability when writing about the capacity of systems, organisations, or countries: “Renewable energy capability is growing rapidly.” Choosing the right word boosts your lexical resource score.