Definition
A phrase used to indicate that something is uncertain or unpredictable; it expresses doubt or a lack of knowledge.
谁也说不准
Will they accept the proposal? Who can say?
他们会接受这个提案吗？谁能说得准呢？
How will this new technology affect our future? Who can say?
这项新技术将如何影响我们的未来？谁能说得准呢？
Will the stock market go up or down tomorrow? Who can say?
股市明天会上涨还是下跌？谁能说得准呢？