Today's Native Mandarin Expression: 摸魚摸到大白鯊 - This is used in Taiwan, not sure if it's common in China. 

 

        First of all, there's a Mandarin idiom called 『 混水摸魚 Hún shuǐ muō yú 』 it literally means to kind of grabble fish in a muddy water, whereas it implies obtaining benefits in a chaotic situation.  The term 摸魚 (muō yú) is then borrowed to mean being slack or doing something in a slack manner. 

Therefore, 上班摸魚 (Shàngbān muō yú) simply means slacking off at work.  What if your colleague isn’t focused on working instead of going on Facebook, playing farm games, or get onto porn website? Which Chinese phrase should you use to kindly warn him? That is…

 

小心！別摸魚摸到大白鯊！ - Xiǎoxīn! ! Bié muō yú muō dào dàbái shā /

Be careful! Don’t get caught for slacking off at work by boss. 

Chinese Grammar Point – Verb + 到

an action and the result of the verb is completed/achieved

1. 你一定要去找 

Nǐ yīdìng yào qù zhǎo  (Not found yet because there’s no 到 after  找)

You must go look for it!

2. 我找到了！  

Wǒ zhǎodào le (By adding 到 after 找, it means the action or the result of the verb is successful and completed)

I found it!

1. 聽 tīng – to hear/listen to - 聽到 tīng dào – heard

2. 講到  jiǎng dào – When it comes to…

3. 看 Kàn – look at…  - 看到  Kàn dào – saw