5 sentences for 大事 (dà​shì — milestone)

1. 结婚是人生的一件大事。

   jié​hūn shì rén​shēng de yī jiàn dà​shì.

   Getting married is a major event in life.

   Source: Dong Chinese Dictionary

2. 那可是件大事啊。

   nà kě shì jiàn dà​shì a.

   That's kind of a big deal.

   Source: OpenSubtitles

3. 这种大事你可千万不能胡来。

   zhè zhǒng dà​shì nǐ kě qiān​wàn bù néng hú​lái.

   You absolutely must not act recklessly in such an important matter.

   Source: Dong Chinese Dictionary

4. 这是件大事。

   zhè shì jiàn dà​shì.

   This is a big deal.

   Source: OpenSubtitles

5. 她还在慎重考虑自己的终身大事。

   tā hái zài shèn​zhòng kǎo​lǜ zì​jǐ de zhōng​shēn dà​shì.

   She is still carefully considering the major event of her life: marriage.

   Source: Dong Chinese Dictionary