Meaning of “tell sb/sth apart” - Learner’s Dictionary

tell sb/sth apart

phrasal verb with tell uk us /tel/ verb (past tense and past participle told)

to be able to see the difference between two things or people that are very similar:

It's impossible to tell the twins apart.

(Definition of “tell sb/sth apart” from the Cambridge Learner’s Dictionary © Cambridge University Press)