Could it also be "very" ?
It is accepted
Doesn't 'hay' mean 'interesting'?
why isn't it 'rất tốt"?
most of the answers here need to be fixed. really = very. really well, very well are the same.
Many sentences insist that you use "thật" for "really" and "rất" for "very", otherwise you're marked wrong. If they're doing that, at least they should be consistent.
I sounds like a teenage expression; "oh like wow, he like teaches sooo good".
I wish this app used English.