4 sentences

1. 大病初愈，他感到全身无力。

   dà​bìng chū yù, tā gǎn​dào quán​shēn wú​lì.

   Having just recovered from a serious illness, he felt weak all over.

   Source: Dong Chinese Dictionary

2. 大病一场后，他还没恢复元气。

   dà​bìng yī cháng hòu, tā hái méi huī​fù yuán​qì.

   He hasn't fully recovered his strength after a serious illness.

   Source: Dong Chinese Dictionary

3. 他大病初愈，身体还非常虚弱。

   tā dà​bìng chū yù, shēn​tǐ hái fēi​cháng xū​ruò.

   He has just recovered from a serious illness and is still very weak.

   Source: Dong Chinese Dictionary

4. 他在大病初愈后，需要一段时间来调理身体。

   tā zài dà​bìng chū yù hòu, xū​yào yī duàn shí​jiān lái tiáo​lǐ shēn​tǐ.

   After recovering from a serious illness, he needs some time to nurse his health back to normal.

   Source: Dong Chinese Dictionary