can't say for sure
将来的事说不准
You never know what the future holds.
— 豹 (1963)
谁输谁赢还真说不准呢
It's really hard to say who'll win and who'll lose.
— 大红灯笼高高挂 (1991)
谁也说不准接下来会发生什么。
No one can say for sure what will happen next.
还未必坐车呢说不准还走着来呢
They might not even take a vehicle—who knows, they might walk here.
— 密阳 (2007)