I think Ami can also understand River pretty well by now.

Not that May understands exactly *what* River's talking about, but she can pick out the gist enough to know that Tara's not out of her body, but whatever's really happening is probably magical and thus out of her league.

(And I spent part of this weekend attempting to clean out my office and stumbled across some old AP English notes, so reading that I went, "Wow, it's like deciphering something Mrs. Snyder would try to throw at us to make sure we were awake!")