can never tell，永遠不知道，永遠搞不清。
You can never tell what he's
thinking.
你永遠不會知道他在想什麼。
You can never tell what it will be
like.
你永遠不知道它是什麼樣。
You can never tell what will
happen next.
誰也不知道馬上會發生什麼。
I suppose the lesson is that you
can never tell what will happen.
我獲得的經驗是，你永遠無法知道未來將會發生什麼事。
You can never tell.
你說不準。