3 sentences

1. 他的精神状态是脆弱的。

   tā de jīng​shén​zhuàng​tài shì cuì​ruò de.

   His mental state is fragile.

   Source: CCMatrix

2. 最让我担心的是他的精神状态。

   zuì ràng wǒ dān xīn de shì tā de jīng​shén​zhuàng​tài.

   What worries me the most is his mental state.

   Source: CCMatrix

3. 幸福是一种精神状态，它是绝对免费的。

   xìng​fú shì yī​zhǒng jīng​shén​zhuàng​tài, tā shì jué​duì miǎn fèi de.

   Happiness is a state of mind and it is absolutely free.

   Source: CCMatrix