2 sentences

1. 他决定改过自新，从此做一个正直的人。

   tā jué​dìng gǎi​guò​zì​xīn, cóng​cǐ zuò yī gè zhèng​zhí de rén.

   He decided to turn over a new leaf and lead an honest life.

   Source: Dong Chinese Dictionary

2. 社会应该给那些失足青年一个改过自新的机会。

   shè​huì yīng​gāi gěi nà​xiē shī​zú qīng​nián yī gè gǎi​guò​zì​xīn de jī​huì.

   Society should give young people who have gone astray a chance to turn over a new leaf.

   Source: Dong Chinese Dictionary