Question

【题目】Why don't you tell him about it?
tell him about it?

Answer 1

【答案】Why；not
【解析】原句意为“你为什么不告诉他这件事呢”，Why don't you do sth.意为“你为什么不...”，其同义句型为Why not do sth.Why don't you=Why not ,所以答案是Why not。