3 sentences

1. 你别这么拘谨嘛。

   nǐ bié zhè​me jū​jǐn ma.

   Don't be so reserved.

   Source: OpenSubtitles

2. 他在陌生人面前显得有些拘谨。

   tā zài mò​shēng​rén miàn​qián xiǎn​de yǒu​xiē jū​jǐn.

   He appears a bit reserved in front of strangers.

   Source: Dong Chinese Dictionary

3. 他的写作风格过于拘谨，缺乏灵活性。

   tā de xiě​zuò fēng​gé guò​yú jū​jǐn, quē​fá líng​huó​xìng.

   His writing style is too stiff and lacks flexibility.

   Source: Dong Chinese Dictionary