know the truth

1. His secret died with him, and now we shall never know the truth.
他的秘密随他一起离去,现在我们永远也不可能知道真相了。

来自《简明英汉词典》

2. I want to know the truth about this matter.
我要知道这件事的真情。

来自《现代汉英综合大词典》