tell the difference between

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: difference, tell
References in classic literature ?
Couldn't ever tell the difference between a sheet and a tackle, simply couldn't.
I don't Know if people can tell the difference between DRINKING that and a bottle of Alpine spring water, unless I need to see the doc about my taste buds.
can buy a cut-price suit along with your groceries - and can most of us even tell the difference between budget or blowout?
Pensioners' Forum Wales says member of the public can find it hard to tell the difference between charity collection bags and ones that private companies use to collect goods that they sell to make a profit.
2 : to be able to tell the difference between things <He can discriminate among the birds by their calls.
The e-tongue is still in development at Barcelona's Institute of Microelectronics, but can already tell the difference between several grape varieties and vintages.
From the basics of meditation and releasing blockages that prevent hearing the divine voice inside to learning to tell the difference between divine and other voices, this is a key acquisition for any spiritual library.
Can you tell the difference between a coyote and a dog?
He said: "Couldn't he tell the difference between a car and a boat?
Merrydown has defied anyone to tell the difference between new PET bottles and its glass packaging.
A series of disturbing events force Trevor to question his state of mind as he increasingly struggles to tell the difference between fantasy and reality - but uncovering the truth proves to be a dangerous quest.
They could tell the difference between duets and warnings.
Cops, prosecutors and judges have found that it isn't as hard as they had feared to tell the difference between a weekend smoker and a medical patient with a doctor's approval.
It's pretty hard to immediately tell the difference between this tiny, threadlike thing and a root hair," says Paul Marek.
M4/M4A1 carbine, NSN 1005-01-361-8208 (The best way to tell the difference between the M16 and M4 BFA's is to remember the M16's is red and the M4's is yellow.