Chinese phrase translation: 白搭 (báidā) no use

白搭 (báidā) no use/ in vain

Usage:

“白搭”是一个口语词，常常指某种做法、想法没有用处或没有效果。此外，它还有浪费时间或力气的意思，常用于为做某事付出很多，但没有达到理想效果这样的语境。
"白搭(báidā)" is a colloquial word. It means certain ways or ideas are of no use or inefficient. It also indicates that it is a waste of time and energy to do something without achieving the expected results.
Sentences:

1、 Xuéxí hànyǔ, fāngfǎ hěn zhòngyào, dànshì rúguǒ bù nǔlì yěshì báidā.
学习汉语，方法很重要，但是如果不努力也是白搭。
A good method for learning Chinese is important, but it would be useless if you do not put efforts into it.
2、 Wèile zhège kǎoshì, wǒ zhè yìzhōu měitiān dōu áoyè kàn shū, jiéguǒ háishì bù jígé, ai, yìzhōu de shíjiān quán dōu báidā le.
为了这个考试，我这一周每天都熬夜看书，结果还是不及格，唉，一周的时间全都白搭了。
I stayed up late all week for this exam, but still failed. It seems that all my efforts are spent in vain.