割鸡焉用牛刀

gē jī yān yòng niú dāogejiyanyongniudao

1. lit. why use a pole-ax to slaughter a chicken? (idiom)
2. fig. to waste effort on a trifling matter
3. also written 殺雞焉用牛刀|杀鸡焉用牛刀[sha1 ji1 yan1 yong4 niu2 dao1]

Study it in Yanamino