Does Chinese have a phrase equivalent to "For all I know"? There is an expression in English:

&quot;For all I know, ....&quot;

The following clause often has a modal expressing uncertainty or the hypothetical nature of the assertion, like &quot;might&quot;, &quot;may&quot;, &quot;could&quot;, or &quot;would&quot;.

For all I know, he might have gone abroad.
For all I know, she doesn't even work there anymore.
For all I know, the test hasn't even been written yet.

The usage is usually something like this. You are talking about some topic. You disavow even a basic level of certainty about the topic by saying &quot;For all I know, X&quot;, meaning something like &quot;I can't even be sure that X isn't true. How can I say anything useful about the topic, if I can't even rule out possibility X?&quot;
This is not the same as &quot;To the best of my knowledge, X&quot; (which means you really think X, you are just saying you are unsure). I think that &quot;As far as I know&quot; is more like &quot;To the best of my knowledge&quot; than &quot;For all I know&quot;, but I think it might have some flexibility. I don't know.
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So, my question is whether Chinese has any equivalent phrases or ways to express &quot;For all I know&quot;? I've seen a few instances of 据我所知, but I don't know whether that's idiomatic Chinese or just a stilted and academic translation. Also, I don't know whether it really has any of the same implications that &quot;For all I know&quot; has. For all I know, 据我所知 is just a neutral statement like &quot;To the best of my knowledge&quot;!
I can only give some possible translations based on your explanation of "For all I know":


  For all I know, he might have gone abroad.
  
  他说不准出国了呢。 
  
  For all I know, she doesn't even work there anymore.
  
  她没准已经不在哪工作了呢。
  
  For all I know, the test hasn't even been written yet.
  
  测试题说不准还没出呢。


We would use "说不准" "没准" and things like that to express the uncertainty. I can't think of one phrase that would have the same meaning of "For all I know" as your explained.