"Ably" is an adverb. http://mw1.m-w.com/dictionary/ably
The verb is able; the complete verb is 'are able to know'.
There is no verb form for the adjective able.
"Be able" is a verb phrase consisting of the verb "be" and the modal verb "able." It is used to indicate capability or possibility.
Poder is the un-conjugated verb for "to be able". So that would most likely be the best verb in this case.
able is not a verb
Enable is a verb that is close in meaning to able. It can be used in different ways, but one of the meanings is "to make able."
In the past, we say - I was able to do it, or in the negative, I couldn't do it/I wasn't able to do it.
ably
Yes. eg - use = usable. But now useable is not a verb it is an adjective.
The word "can" is a verb. The infinitive is "to be able to", it is a modal verb.
The verb in the sentence is: can walk.The word 'can' is functioning as an auxiliary verb (helper verb) that modifies the main verb 'walk' as 'able to'.
The verb form of "breakable" would be "break."