Can the volitional form be used when the speaker is not intending to do the action themselves?

Question

From what I understand the volitional form is often used to mean "let's do" something, e.g. 行こう can mean "let's go". Can this form be use when the speaker themself is not going to perform the action? For example, in English a teacher might say, "Let's all do well on the test tomorrow!", even though she isn't actually going to take the test herself (my Japanese is terrible, but something like 「明日は試験を退けよう！」)? Could you use the volitional form in this case?

A second, similar question, if you don't mind. Could the volitional form be used in a case where neither the speaker or the listener will perform the action? Such as in a science documentary, when the narrator might say something like "Let's try mixing sulphuric acid with sugar", even though the actual mixing is not being done by the narrator or the viewer.

Thank you!

Answer 1

Yes, it can. I remember my teacher at school (here in Japan) sometimes using 頑張りましょう when talking about activities that he would not directly take part in. He was however peripherally involved, like being the one setting the test he was referring to with his 頑張りましょう。

I'd say that there needs to be at least a link between the person using this form and the activity. It doesn't need to be a direct link, but the speaker needs to be involved in some way by either the activity or its outcome.

Similarly I have heard narrators using this form in documentaries on TV. Again, even though they do not perform the action necessarily, the action and outcome impacts the course of the documentary and also hence also the narrator.