"What will have happened?"
Translation:O que terá havido?
Apart from the intolerant outrage, I have to agree with loismen. "O que terá acontecido?" should translate to "What has happened?" or, even better, "What in the world has happened?" (just to show that we actually use "terá" as emphasis, not future).
"O que terá acontecido até 2020?" could be translated as "What will have happened by 2020?". The time mark makes it clear that it is future.
PS I'm Brazilian, BTW
"O que vai ter acontecido?" or "O que terá acontecido?" are both also correct. I am brazilian and we use that naturaly.
When am I supposed to use "o" in front of "que" and when is either acceptable? This is driving me crazy.
«o que» is an abbreviated form of «o que é que...» that is let's say of «what is the thing that...» In french respectively they say « qu'est-ce que ce que...».