所以(suǒ yǐ) - therefore, so, as a result in Mandarin

我wǒ生shēng病bìng了liǎo，所suǒ以yǐ没méi去qù上shàng班bān。

I was ill, so I did not go to work.

因yīn为wèi下xià雨yǔ，所suǒ以yǐ我wǒ们men没méi去qù。

Because of the rain, we therefore did not go.

你nǐ努nǔ力lì学xué习xí，所suǒ以yǐ成chéng绩jì很hěn好hǎo。

You study hard, so your grades are very good.

天tiān太tài黑hēi，所suǒ以yǐ我wǒ们men回huí家jiā了liǎo。

It got too dark, so we went home.

他tā没méi准zhǔn备bèi好hǎo，所suǒ以yǐ输shū了liǎo。

He was not prepared, so he lost.