which is which

Idioms

What particular one is what particular one, or what is the difference between different ones. For example, These twins look so much alike I can't tell which is which, or Both our raincoats are tan; do you know which is which? This idiom was first recorded about 1412.

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

which is which

Having someone as clumsy as Zacharia for a mouthpiece makes it easier to tell which is which.

From Slate ● Oct. 15, 2026

Often companies have a hard time distinguishing which is which.

From The Wall Street Journal ● Sep. 16, 2026

Knowing which is which can save you a surprising amount of December stress.

From Salon ● Dec. 23, 2025

The detection process is time-consuming for human observers - but Squirrel Agent uses the power of AI to rapidly analyse all those markers and decide with an extremely high level of accuracy which is which.

From BBC ● Nov. 23, 2024

I can’t tell which is which, because they’re the muscle.

From "The Inquisitor's Tale" by Adam Gidwitz

Random Word

Spin the wheel and learn a new word!

Get a word

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023