是骡子是马，牵出来遛遛

shì luó zi shì mǎ , qiān chū lai liù liushiluozishima,qianchulailiuliu

1. lit. to see whether it's a mule or a horse, take it out for a walk (idiom)
2. fig. the proof of the pudding is in the eating
3. to show what one is made of

Study it in Yanamino