In the imperfect, poder indicates capability with regard to something in the past but
not necessarily fulfilment of the action referred to.
Fernando podía arreglarlo.
Fernando was capable of repairing it. (but may not have actually done so)17.4 (p. 75); 17.3 (p. 74)
53.1.2 Using a single verb to express capability or incapability
Capability or incapability are sometimes expressed, not by poder+ infinitive but by a
single verb, for example:
¿Entiendes?
Can you understand?
No entiendo nada.
I can’t understand anything.
¿Lo oyes?
Can you hear it?
No oigo bien.
I can’t hear well.
Desde aquí veo todo.
I can see everything from here.
No siento nada.
I can’t feel anything.17.1.1 (p. 72)
53.1.3 (No) ser capaz de+ infinitive
Ser capaz de, ‘to be able to’, is much less common than poder, and it indicates stronger
capability or incapability.
¿Eres capaz de saltar esa reja?
Are you able to jump over that fence?
No es capaz de hacerlo.
He/she is not able to do it.
¿Seríais capaz de escalar esa montaña?
Would you be able to climb that mountain?
Por supuesto que seríamos capaces.
Of course we would be able to.53.2 Enquiring and making statements about learned abilities
53.2.1 Saber+ infinitive
To enquire and make statements about learned abilities, as in ‘Can you play the piano?’,
‘She can swim quite well’, Spanish uses the construction saber, literally to know, plus
infinitive, not poder.EXPRESSING CAPABILITY AND INCAPABILITY 53.2