As practice I have been alternately translating short bits of writing both from Japanese to English and from English to Japanese. When most recently attempting the latter, it occurred to me that I have never (that I can recall) seen a way to specify 'will not' that isn't ambiguous with 'cannot' or 'does not'.
For example, the stock translation of 'I will not forgive you' (許さない) is distinguished from 'I cannot forgive you' (許せない) but not from 'I do not forgive you' (許さない again).
Some of the time this isn't a problem, but especially when writing in a 3rd person perspective, the implications of doesn't vs won't can be significant (i.e. 'The man didn't tell her his name' implies nothing in particular, but 'The man would not tell her his name' implies that the question of the man's name was explicitly rebuffed, suggesting suspicion, secrecy, or just plain rudeness).
In that specific example, the distinction could be made with a sentence like '彼女は尋ねたのに男は名前を言わなかった', or '男は彼女に名乗らないと言った', these approaches cannot always be used and require more information than might be available. Is there a more general way to distinguish between 'cannot'/'does not' and 'will not' in Japanese, either explicitly or by changing the sentence structure?
Since the current answerers seem to have misunderstood my question, I will attempt to clarify here. Firstly, I am not intending to conflate or group together 'cannot' with 'does not', except in that they are both alternatives to 'will not'.
Secondly, the distinction I'm trying to make between the two and 'will not' is not one of tense (present/past vs future) but one of intent. 'I cannot tell you' implies a very different intent than 'I will not tell you', and it is this difference which I am trying to express in Japanese.