拉牛上樹 [－－－树]

Jyutping laai1 ngau4 soeng5 syu6
Pinyin lā niú shàng shù

Definitions (CC-CANTO)
  1. to try and do something that is almost impossible to achieve
Definitions (粵典–words.hk)
  1. 語句
    取​唔​到​實效
    to have a vain attempt to do something; literally: to pull a cow up a tree
Definitions (Kaifangcidian)
  1. 趕鴨子上架 – 赶鸭子上架