You're old enough to distinguish between fact and fantasy.
I have trouble distinguishing between the two of them.
I have trouble distinguishing the difference between the two of them.
You should be able to distinguish fact from fantasy.
The only thing that distinguishes the dogs is their bark.
The singer's voice is what distinguishes the band.
You can't distinguish the detail from this distance.
Origin of DISTINGUISH
alteration of Middle English distinguen, from Anglo-French distinguer, from Latin distinguere, literally, to separate by pricking, from dis- + -stinguere (akin to Latin instigare to urge on) — more at stick