1(after a noun N and before a predicate P) the reason why N P
2Example: 我之所以討厭他|我之所以讨厌他 "the reason why I dislike him (is ...)"
Examples
tā men他们zhī suǒ yǐ之所以méi yǒu没有yóu yǒng游泳，jiù就yīn wèi因为tiān qì天气hěn很lěng冷。
他们之所以没有游泳，就因为天气很冷。
They didn't swim because it was cold.
我们罢工之所以是因为公司没有涨我们的工资。
The reason we're on strike is that the company hasn't improved our wages.
我们之所以罢工是因为公司没有改善我们的工资。
We're on strike because the company hasn't improved our wages.