Translation:Are you serious?
The phrase most often used by participants in this tree!
i'm only a heritage speaker but i'm pretty sure 认真 isn't really used this way?
认真 is diligent, hard working or earnest. This translation is a bit strange. It shouldn't be "serious" but "hard working"
Yeah this is odd. 认真 is closer to "earnest." Or "taking something to heart."
I dont understand the grammar here. Is 的 used to make the adjective 认真 become a noun?