做手脚 (zuò shǒujiǎo)to tamper with something; to play a trick

Usage:

“做手脚”的意思是为达到目的,暗中进行某种活动或者使用不好的手段,是个贬义词。口语中还经常说“在……上做(了/过/的……)手脚”。
As a derogatory term, “做手脚”( zuò shǒujiǎo) refers to do something secretly or employ bad means in order to achieve certain goals. People often say “在……上做(了/过/的……)手脚”.(zài ……shàng zuò (le /guò /de)shǒujiǎo)

Sentences:

1、Xiǎo shāngfàn zài chèng shàng zuò shǒujiǎo de shìqing, jīhú suǒyǒu rén dōu yùdào guò.
小商贩在秤上做手脚的事情,几乎所有人都遇到过。
Almost everyone has encountered that peddlers play tricks on the scales.

2、Lǎobǎn zài xiāoshòu’é shàng zuò le shǒujiǎo, běnlái shì xiǎng shǎo jiāoshuì. Ta tōushuì de shì bèi fāxiàn hòu, què bèi fá le gèngduō de qián.
老板在销售额上做了手脚,本来是想少交税。他偷税的事被发现后,却被罚了更多的钱。
In order to be lightly taxed, the boss had cheated on the sales volume. However, he was fined more after being discovered.

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