5 sentences

1. 他心眼多，在生意场上从来没吃过亏。

   tā xīn​yǎn duō, zài shēng​yi chǎng​shàng cóng​lái méi chī guo kuī.

   He is very shrewd and has never lost out in business.

   Source: Dong Chinese Dictionary

2. 他这人做事没准，你最好多留个心眼。

   tā zhè rén zuò​shì méi​zhǔn, nǐ zuì hǎo duō liú gè xīn​yǎn.

   He is unpredictable; you'd better be a bit more cautious.

   Source: Dong Chinese Dictionary

3. 那人性格极奸，你平时要多留个心眼。

   nà rén xìng​gé jí jiān, nǐ píng​shí yào duō liú gè xīn​yǎn.

   That person is extremely treacherous; you should be more cautious.

   Source: Dong Chinese Dictionary

4. 谁都看得出来，他没安好心眼。

   shéi dōu kàn de chū lái, tā méi ān hǎo xīn​yǎn.

   Anyone can see that he has bad intentions.

   Source: Dong Chinese Dictionary

5. 做人得凭心眼，不能干那种亏心事。

   zuò​rén děi píng xīn​yǎn, bù néng gàn nà zhǒng kuī​xīn​shì.

   One should live with a conscience and not do things that go against it.

   Source: Dong Chinese Dictionary