Modal verbs: ability

MODAL VERB	TENSE	EXAMPLE
(be) able to (be) not able to	present	I am able to swim
(have) been able to (have) not been able to	present perfect	She has been able to finish the book.
can can´t	present	I can swim
could couldn´t	past - general ability	I could swim when I was 3 years old.
managed to wasn´t/ weren´t able to / couldn´t	past - specific ability	There was a terrible fire, but everyone was able to escape.
to be able to not to be able to	infinitive	They hope to be able to visit us next week.
was/were able to wasn´t/ weren´t able to / couldn´t	past - specific ability	There was a terrible fire, but everyone was able to escape.
will be able to won´t be able to	future	I will be able to help you tomorrow.
would be able to	conditional	If you saved enough money, you would be able to go on holiday.