Definition
Used to express uncertainty or the inability to predict something; it implies that no one knows the answer.
谁能知道？
"How will this company develop in the future?" "Who can say? The market changes too quickly."
「这家公司未来会如何发展？」「谁能说得准呢？市场变化太快了。」
"Will they eventually get married?" "Who can say? Their current relationship is very unstable."
「他们最终会结婚吗？」「谁能说得准呢？他们现在的关系非常不稳定。」
"Will this new policy be successful?" "Who can say? We'll just have to wait and see."
「这项新政策会成功吗？」「谁能说得准呢？我们只能等着看了。」