私自

fǎ lǜ shì shén shèng de bù róng sī zì cuàn gǎi

法律是神圣的，不容私自篡改。

The law is sacred and cannot be tampered with.

xiǎo hái zi sī zì xià hé yóu yǒng shì hěn wēi xiǎn de

小孩子私自下河游泳，是很危险的。

It is very dangerous for children to swim in the river privately.

bù kě sī zì nuó yòng gōng kuǎn

不可私自挪用公款。

Don't illegitimately use public funds.

sī zì táo pǎo

私自逃跑

escape secretly

sī zì gǎi dòng

私自改动

tamper without authorizatio

sī zì xià zài

私自下载

download privately

sī zì jiē rù

私自接入

privately network access

sī zì xié chū

私自携出

take out without permission