viernes, 1 de abril de 2016

Unit 2 Grammar Can and be able to

UNIT 2
Ability: Can and be able to
1.    Can and be able to: Are the verbs most commonly used to talk about ability. Sometimes we can use either verb without changing the meaning of the sentence. Sometimes, we have to use be able to when there is no appropriate form of can.
Infinitive                      be able to
Present                       can or am / are / is able to
Future                         will be able to
Past                            could or was / were able to
Present Perfect          have / has been able to
Past Perfect                had been able to
2.    Present ability: both forms are possible, but can is more usual.
Gareth can run very fast. (Gareth is able to run very fast.)

To talk about a learned ability in the present, can is more usual. “Know how to” can be used as an alternative to can.
            Can you play chess? / Do you know how to play chess?
3.    Future ability: we use the future form of be able to
Will I be able to play better after I´ve had some lessons?
4.    Past Ability: both forms are possible.
Before his accident, Ben could jump really high.
Before his accident, Ben was able to jump really high.
To talk about an ability to do something in the past on one particular occasion, we must use the past tense of be able to or
 manage (+ to + infinitive)
 or succeed (+ in + ing)
                        Although she had lost a lot of blood, the doctors were able to save the girl´s life.
Despite the difficult conditions, the surgeon  manage to perform the operation successfully and succeeded in saving the man´s leg.
NOTE: If the event was unsuccessful, it´s possible to use couldn’t as well as the past form of be able to, manage and succeed.
                        Although he did his best, he couldn´t finish in time.
           
5.    ´Conditional ability´: to talk about a hypothetical ability in the present or future, we can use could or would be able to:
I could probably jump further if I had longer legs.
I would probably be able to play better if I practised more.
To talk about a hypothetical ability in the past, we usually use could + have + past participle, although we can also use would have been able to:
                        Even if he´d been taller, he couldn´t have reached it.
                        Even if he´d been taller, wouldn´t have been able to reach it.

6.    Other structures used to talk about ability:
Aptitude and capacity for doing sth, we can use be capable of + ing
             He is certainly capable of breaking the world record.
To talk about how well we do sth, we can use the structure be good (brilliant, etc) / bad (terrible, etc) at + noun or gerund:
            I have never been good at sports.

            I am particularly bad at running.

No hay comentarios:

Publicar un comentario