2 sentences for 深沉 (shēn​chén — reserved)

1. 他性格深沉，很少向人吐露心声。

   tā xìng​gé shēn​chén, hěn shǎo xiàng rén tǔ​lù xīn​shēng.

   He has a reserved character and rarely confides in others.

   Source: Dong Chinese Dictionary

2. 他是个深沉的人，喜怒哀乐从不外露。

   tā shì gè shēn​chén de rén, xǐ​nù'āi​lè cóng bù wài​lù.

   He is a reserved person and never shows his emotions.

   Source: Dong Chinese Dictionary