Barry!Barry Hofstetter wrote:I'm glad that you said "other verbal forms" because only one of these is an infinitive, and so prove nothing about the infinitive. Again, this reflects more the translator's sense of how best to render the English than it does about anything inherent in the verbal form itself. Each of them could reasonably be rendered without the quality of "ability" added. If that implication is there, it's solely due to the context, and not the verbal form so used.
I think the nub of the problem is that we don't have a 'Potential Mood' in either Greek or English, such as in Japanese. The subjunctive can express potential, volition, or cognition which is often decided by syntax or context; otherwise the exact force must be left undetermined, usually in situations where it is irrelevant.
The concept of ability, however, often does impact on the verbal meaning; but because we don't have a potential mood we tend to ignore it; it becomes tedious to express it in every instance. It is forced to our attention (or should be) in certain contexts such as when we want to acquire a certain faculty as in Acts 4:29.
I would dispute that it is solely contextually determined. It may also be determined lexically. e.g. 'I can persuade him' makes better sense than 'I persuade him'.