tell the difference between (someone or something)

tell the difference between (someone or something)

To be able to discern or distinguish some person or thing as being distinct and unique compared to someone or something else. It's very difficult to tell the real paintings from the counterfeits, but there are a few things we can look for to be sure. Even I have trouble telling the difference between the two brothers, so I can understand your confusion. The court ruled that the man was psychologically unable to tell the difference between right and wrong when he committed the crime.
See also: between, difference, tell

tell the difference between (someone and someone else) (or something and something else)

to recognize the things that distinguish people or things. I can't tell the difference between Billy and Bobby. Sam can't tell the difference between Granny Smith and Royal Gala apples.
See also: between, difference, tell