Reading a lesson on 国語文法.com, I'm having difficulty telling 意志 from 勧誘.
E.g. 「今度こそ成績をあげよう。」 is stated is that of volition (意志). However, why can't it be "(I suggest you to) improve your grades!"?
Or the following example/exercise sentence: 彼の業績は評価しよう - is that the speaker's intention to evaluate 3rd party performance, or a suggestion to 2nd party to do that?
Or an image like this, is it the speaker's (猫さん's) intention or suggestion for the reader (a motivational image)?
It might be easier to visualize this as the ambiguity of me/us, rather than a clear distinction between volition/suggestion.
When one says 成績を上げよう, it may seem to an English brain that it is either “Let me improve my grades” or “Let us improve our grades”. In fact, the mental image in my Japanese brain is more like “Let it be that grades are improved”. There is an inherent fuzziness to the me/us. In this case I might even say the me/us is nonexistent.
In the example 山を見よう, it is like “Let [me/us] look at the mountain”, where [me/us] is a single ambiguous clump that isn't actually teased apart at the point of speaking nor receiving. It safely remains as a clump, until called upon to provide a clear English translation.
