他们在街上偶然相遇。

Tāmen zài jiē shàng ǒurán xiāngyù.

We occasionally meet in the street.

我偶然会在咖啡店里看到他。

Wǒ ǒurán huì zài kāfēidiàn lǐ kàndào tā.

I occasionally see him in the coffee shop.

我偶然发现了这里有一家中国餐馆。

Wǒ ǒurán fāxiànle zhèlǐ yǒu yì jiā Zhōngguó cānguǎn.

Incidentally I discovered there is a Chinese restaurant in here.