to be able to do sth (of acquired skills) saber hacer algo; (other contexts) poder hacer algo; the child isn't able to walk (yet) el niño no sabe andar (todavía); he's not able to walk no puede andar; come as soon as you are able ven en cuanto puedas; I was eventually able to escape por fin pude escaparme; por fin logré escaparme; able to pay solvente
2 (capable) [+person] capaz; [+piece of work] sólido
she is one of our ablest pupils es una de nuestras alumnas más capaces
able seaman (n) marinero (m) de primera or patentado
Poder and saber can both translate to be able to, can and could.
Use saber when to be able to, can and could mean "know how to":
Can you type? ¿Sabes escribir a máquina?
His wife couldn't drive Su mujer no sabía conducir
Generally, use poder:
He can stay here Puede quedarse aquí
We have not been able to persuade them No hemos podido convencerlos
When can and could are followed by find or a verb of perception - see, hear, feel, taste or smell - they are usually not translated:
I can't find it No lo encuentro
What can you see? ¿Qué ves?
When to be able means "to be capable of", you can often use ser capaz de as an alternative to poder:
I don't think he'll be able to resist it No creo que sea capaz de or pueda resistirlo