Como dizer "se a carapuça servir..." em inglês

Adorei a dica, Flávia...

Depois de uma pesquisa, eu descobri que hoje em dia se usa mais "If the shoe fits, wear it", e que, muito provavelmente, isso se deu por causa do conto da Cinderella.

"If something applies to you, accept it, as in These problems are hard to solve, and most people would need help, so if the shoe fits, wear it! This expression originated as if the cap fits, which alluded to a fool's cap and dates from the early 1700s. Although this version has not died out entirely, shoe today is more common and probably gained currency through the Cinderella fairy tale, in which the prince sought her out by means of the slipper she lost at the ball."

Fonte: http://www.answers.com/topic/if-the-shoe-fits-wear-it

Obrigada por atualizar, Laís!

Segundo esse podcast, existem expressões diferentes entre inglês britânico e o americano:
https://castbox.fm/vb/93699359

- Britânico: "If the cap fits wear it"

- Americano: "if the shoes fit wear it"