Able

Able /ˈeɪbəl/ adj.

Read the sentences, then guess the meaning of the word able.

 * I was just able to reach the handle.
 * I've always wanted to be able to speak Japanese.

having the skill, strength, knowledge, etc. to do something

 * Will you be able to come tonight?
 * I'd like to do more gardening, but I never seem able to find the time.
 * I haven't been able to read that report yet.

in a situation in which it is possible for you to do something

 * an able student
 * one of my more able students

Meaning in context
If you see be able to do patten, then it must be the 1st or 2nd meaning. If you means ability, it must be the 1st mean. But if you means possibility, it's the 2nd meaning.However, if you didn't see the pattern, but it use as normal adjective before nouns, then it's the 3rd one.

What does able mean in the following sentence?

 * Mrs Thomas is a very able teacher.
 * I never realized how much I really enjoyed school until I wasn't able to attend.
 * She was widely regarded as one of the most able members of the president's staff.
 * I hope one day you will be able to forgive me, not for my sake but for your own.
 * A good speaker is able to expect an audience's needs and concerns.
 * Those bags look really heavy - are you sure you'll be able to carry them on your own?

Word Family & Frequency
able antonym unable

ability antonym inability

ability countable, inability uncountable

ably,abler,ablest from the 3rd meaning of able
 * She was unable to sleep.
 * A manager must have the ability to communicate well. (ability: the state of being able to do something)
 * a young girl with great musical ability (ability: the level of skill at doing something)
 * We blame the addict and alcoholic for their inability to control their drinking.
 * He was ably defended by his lawyer.
 * Mr Jonathan, an abler leader than many in his own party give him credit for, is likely to try to finish his power-sector reforms.
 * He is regarded as India's ablest working Cabinet man.
 * America's abilities to influence Pakistan's army are limited.

be able to do, can
For ability, be able to stress that what you can do need a lot of effort, skill, or knowledge. For possibility, they are equal.
 * Why didn't they ask me? I could have done it for them for the half price.
 * To take the class, you have to be able to use a computer.
 * Can you come to my place tomorrow and help me move some furniture?

able, good
For person, able stress that he good at tasks and activities that require intelligence or academic ability
 * She's a really good actor.
 * He was a very able man in business matters.

ability, capability, capacity, power
capability and capacity are rather formal
 * Does the country have the capability to produce nuclear weapons?
 * Children have a special capacity for learning language.
 * Only the police have the power of arrest.

skill, ability, talent, gift, aptitude

 * The men rode their horses with great skills.
 * She has great athletic ability.
 * He has a remarkable musical talent.
 * He has a gift for languages.

V+J
be, feel, seem, prove

R+J
fully, perfectly, quite, well better, more uniquely just
 * He is well able to take care of himself.
 * Once you've had some sleep, you'll feel better able to cope(= to succeed in dealing with difficult problem or situation).
 * Human are uniquely to use true language.

barely, hardly, scarcely financially, physically
 * She was very old and barely able to walk.
 * She is not physically able to take care of herself.

V+J
be, seem
 * She seems very able.

R+J
extremely, fairly, very

reasonably

less
 * less able students

Reference

 * BNC_COCA Word Family List, Version 2.0
 * BYU Frequency Lists
 * Longman Dictionary of American English, 4th Edition
 * Longman Dictionary of Contemporary English, 5th Edition
 * Oxford Learner's Thesaurus
 * Oxford Collocation Dictionary, 2nd Edition