OK, Say You're an Extraterrestrial ...

[sengsational]

Given that we still cannot talk to whales and dolphins in a meaningful way and barely understand dogs, horses to train them, I think that's wildly optimistic

Well, those animals are not really what I was talking about. They might be our best examples of non-human intelligence, but I don't think I'd like to try to teach them calculus. We have machines today that understand what humans say in many languages. We have a machine that can answer questions and can parse out nuance and innuendo (Watson). I find it not so hard to believe that a society that mastered FTL travel couldn't observe a bunch of humans speaking (with closed captions) and then write us a letter and read it to us. But could be I've read too many science fiction books!