Not fair... I reckon it should accept 'This is very simple"
Technically that's "proste", but they are so close that we decided to add it as well.
Yay, finally I win :-)
Thanks! I always understood proste as direct.
I guess the adverb "prosto" can be translated as "direct" in some contexts.
There is a magazine called Wprost.
That is so easy <- not accepted
"so" doesn't equal "very", even if it can be used interchangeably in some contexts. Not this one.