To hope for a good result or to wish for luck in a situation.
You have the interview tomorrow, so keep your fingers crossed for a great opportunity.
你明天有面试,所以希望一切顺利。
To express uncertainty about a future event and hope for a positive outcome.
We're waiting for the test results, so let's keep our fingers crossed for good news.
我们正在等待测试结果,所以让我们希望有好消息。