In Difference between^x, Accusative^x, Anaphoric^x

Hello Dawnstorm, The terminology is not happy, admittedly; "middle voice" and "ergative" belong to other linguistic contexts, as has been mentioned; but I think it can be disentangled. It may be the case that "ergative" usage was once much more common in English....

The problem I see here is a muddle of syntax, pragmatics and semantics. In most of these sentences you could make a case for elided objects, that are taken care off by context (rather than considered irrelevant, as in "I am eating."): e.g. Yes, I saw X. X = anaphoric; referring to...