3 sentences

1. 那一带有很多光棍在闹事。

   nà yī​dài yǒu hěn​duō guāng​gùn zài nào​shì.

   There are many hoodlums causing trouble in that area.

   Source: Dong Chinese Dictionary

2. 他都四十岁了，还是个单身光棍。

   tā dōu sì​shí suì le, hái​shi gè dān​shēn guāng​gùn.

   He is already forty years old and still a bachelor.

   Source: Dong Chinese Dictionary

3. 他可是个老光棍，这点小计谋瞒不过他。

   tā kě​shì gè lǎo guāng​gùn, zhè diǎn xiǎo jì​móu mán bù guò tā.

   He is a seasoned hand; this little scheme won't fool him.

   Source: Dong Chinese Dictionary