4 sentences

1. 这件事由你作主。

   zhè jiàn shì yóu nǐ zuò​zhǔ.

   It is up to you to decide on this matter.

   Source: Dong Chinese Dictionary

2. 这件事由你出名办理比较合适。

   zhè jiàn shì yóu nǐ chū​míng bàn​lǐ bǐ​jiào hé​shì.

   It would be more appropriate for you to handle this matter in your name.

   Source: Dong Chinese Dictionary

3. 这件事由你来开头，后面我接着做。

   zhè jiàn shì yóu nǐ lái kāi​tóu, hòu​mian wǒ jiē​zhe zuò.

   You start things off, and I will take it from there.

   Source: Dong Chinese Dictionary

4. 这件公事由他当事，处理得十分稳妥。

   zhè jiàn gōng​shì yóu tā dāng​shì, chǔ​lǐ de shí​fēn wěn​tuǒ.

   He was in charge of this official matter, and it was handled very reliably.

   Source: Dong Chinese Dictionary