[tell] the difference

to recognize the dissimilarities between two or more things

She could tell the difference between the identical twins by their distinct personalities.
The detective carefully examined the footprints to tell the difference between the suspect's shoes and those of others at the crime scene.
If you look closely, you could tell the difference in color between the two shades of paint.
The jeweler used a magnifying glass to tell the difference between the real and imitation gemstones.
When comparing the paintings side by side, you can easily tell the difference in style and technique.