Grammar Point: 白白 báibái and 白 bái basically share the same meaning. It means to do an action “in vain.” The slight difference is that 白白 báibái is more negative. It emphasizes that the action is a wasted effort.
Structure
白白 + Verb + 了
As you know, Chinese prefers even syllables, so unlike 白 bái, 白白 báibái usually used with two-syllable words, like 浪費/浪费 làngfèi to waste, 準備/准备 zhǔnbèi to prepare, 努力 nǔlì put an effort, etc.
你不來也不告訴我，讓我在餐廳白白等待了你3個小時
你不来也不告诉我，让我在餐厅白白等待了你3个小时
Nǐ bù lái yě bú gàosù wǒ, ràng wǒ zài cāntīng báibái děngdàile nǐ 3 ge xiǎoshí.
Nǐ bù lái yě bú gàosu wǒ, ràng wǒ zài cāntīng báibái děngdàile nǐ 3 ge xiǎoshí.
You didn’t come and never told me, so I waited in the restaurant for 3 hours for nothing.
你真的是白白浪費了自己的時間，30歲的人怎麼能什麼工作都不做，每天打遊戲
你真的是白白浪费了自己的时间，30岁的人怎么能什么工作都不做，每天打游戏
Nǐ zhēnde shì báibái làngfèile zìjǐ de shíjiān, 30 suì de rén zěnme néng shénme gōngzuò dōu bú zuò, měitiān dǎ yóuxì.
You are really wasting your time for nothing. How can a 30-year-old man not do any work and just play games every day.
為了考下個月的HSK考試我每天努力讀書，結果忘了報名，真的是白白準備了
为了考下个月的HSK考试我每天努力读书，结果忘了报名，真的是白白准备了
Wèile kǎo xià ge yuè de HSK kǎoshì wǒ měitiān nǔlì dúshū, jiéguǒ wàngle bàomíng, zhēnde shì báibái zhǔnbèile.
I studied hard every day to take the HSK exam next month, but I forgot to register. So my preparations were all wasted.
白白 + 地 + V + 了
Unlike 白 bái, 白白 báibái can be used as an adverb. And, as I mentioned before, it follows the even syllable rule. When you are using 白白地 báibáidi, usually the following verb is a one-syllable word. However, when you are using 白白地 báibáidi, it actually means you don’t think the action is worth doing.
我請他幫忙介紹工作，結果根本沒消息，真是白白地請了他一頓飯
我请他帮忙介绍工作，结果根本没消息，真是白白地请了他一顿饭
Wǒ qǐng tā bāngmáng jièshào gōngzuò, jiéguǒ gēnběn méi xiāoxí, zhēnshi báibáidì qǐngle tā yī dùn fàn.
Wǒ qǐng tā bāngmáng jièshào gōngzuò, jiéguǒ gēnběn méi xiāoxī, zhēnshi báibáidì qǐngle tā yī dùn fàn.
I asked him to help me with job referrals, but no news at all. I feel I bought him a meal for nothing.
我出門跑步沒想到手機掉了出來摔壞了，白白地丟了台手機
我出门跑步没想到手机掉了出来摔坏了，白白地丢了台手机
Wǒ chūmén pǎobù méi xiǎngdào shǒujī diàole chūlái shuāi huàile, báibáidì diūle tái shǒujī.
I went out for a run and my phone accidentally fell out and broke, so I lost the phone for nothing.
Exception
When it comes to religion, it is always an exception. In the Bible, 白白地 báibáidi focuses on a favor being done for free, without asking for anything in return.
我們只是白白地得恩典
我们只是白白地得恩典
Wǒmen zhǐshì báibáidì dé ēndiǎn.
We only receive grace for free.
神將萬物和祂的兒子一同白白地賜給了我們
神将万物和祂的儿子一同白白地赐给了我们
Shén jiāng wànwù hé tā de érzi yìtóng báibáidì cì gěile wǒmen.
God has given us everything as well as His Son without asking for anything in return.
