TELL

(KNOW) [verb] [past:] told - to know, recognize or be certain"He's Dutch." "How can you tell?" [I]It's too dark for me to tell what it says on the sign. [+ wh- word]I could tell (that) you were unhappy. [+ (that) clause]It's easy to tell a blackbird by/from its song. [T]As babies, the twins were so similar that I just couldn't tell them apart (= didn't know which was which).This coffee is about half the price of that one and yet you really can't tell the difference (= notice any difference in quality).There is no telling (= there is no way of knowing) what the future will hold for them.You never can tell/You can never tell means you can never know or be certain.Who knows what will happen to Peter and me in the future - you can never tell.