3 sentences

1. 良好的开端是成功的一半。

   liáng​hǎo de kāi​duān shì chéng​gōng de yī​bàn.

   A good start is half the battle.

   Source: Dong Chinese Dictionary

2. 兄弟，这是严重精神疾病的开端。

   xiōng​dì, zhèi shì yán​zhòng jīng​shén jí​bìng de kāi​duān.

   This is the beginning of serious mental illness, dude.

   Source: OpenSubtitles

3. 鸦片战争标志着中国近代史的开端。

   yā​piàn zhàn​zhēng biāo​zhì zhe Zhōng​guó jìn​dài shǐ de kāi​duān.

   The Opium War marked the beginning of modern Chinese history.

   Source: Dong Chinese Dictionary