原来 + Clause
The adverb 原来 (yuánlái) means 'it turns out that,' 'originally,' or 'so it was.' It is used to express a realization or discovery about something that was previously unknown or misunderstood. It often introduces surprising or clarifying information in a narrative.
原来你们两个是同学啊,我一直不知道!
Yuánlái nǐmen liǎng gè shì tóngxué a, wǒ yīzhí bù zhīdào!
So you two are classmates! I never knew!
找了半天钥匙,原来在口袋里。
Zhǎo le bàntiān yàoshi, yuánlái zài kǒudài lǐ.
I looked everywhere for my keys, and they were in my pocket all along.
原来他早就知道这件事了。
Yuánlái tā zǎo jiù zhīdào zhè jiàn shì le.
So he knew about this all along.