SYN127 - Subjects in PDE 

Good explanation

Can you please clarify the difference between unergatives and ergatives? Also betwwen accusatives and unaccusatives?? This gets me so confused.

I'd like to reiterate my concern about using the term ergative here: take.ms/spdwV. I think where you are using ergative, the term unaccusative is more appropriate. I prefer to reserve ergatives for transitive constructions. In fact, one of your examples is used on this Wikipedia page for unaccusatives: marker.to/icUxyi