If you look up the definition of grammatical mood on Wikipedia, along with tense and aspect, can you explain why you think this meets the definition of a tense and not a mood?
Anyway, I have put a bit more information about this tense up in the discussion.
No I didn't and I was not being deliberately obtuse. That's not what "some" means here. Pretend I used no word instead of "some" — it would have had the same meaning. I get the impression from your grammar that you are not a native English speaker. That's fine, but then you may not have a complete grasp on something like this.
That wouldn't be changing the meaning. I'm not continuing this conversation because 1) I don't want to argue about the subtleties of English grammar with someone who is not a native speaker, and 2) I don't want to argue about linguistics with someone who doesn't know linguistics (as proven by your pointing to "grammar books" for evidence that it's a tense).
But it can be explicit in Dutch:
Reed dan ook niet zo hard.
(drove then also not so fast)
Frankly, you don't have to take my word for it. I suggest doing some research on how mood and tense work in linguistics. It's not clear to me that you understand what these terms actually mean. Maybe I'm wrong.
The point I am making, is that by the definition of mood, "inferential" simply has to be a mood. The point of using it is to suggest a particular relationship with reality ("I didn't see this, but I heard it second-hand"). That's modality, i.e. mood. It also happens to restrict the temporality of the verb to the past.
> It clearly transmits the essential time information and also adds mood no-confirm structure on top.
What you seem to be referring to here is the actual vocal pattern that you attach to a verb root to signify gossip. Of course, word endings can convey both tense and mood, just as they can convey both gender and number. But they are still separate concepts.
But as per my other comment, if you're just listing all the constructions an English word can take for your students to memorise, you can just call them all tenses and be done with it.