2 sentences for 心机 (xīn​jī)

1. 她心机很深，让人很难完全信任她。

   tā xīn​jī hěn shēn, ràng rén hěn nán wán​quán xìn​rèn tā.

   She is very scheming, making it hard to trust her completely.

   Source: Dong Chinese Dictionary

2. 他花了不少心机才最终说服客户签下合同。

   tā huā le bù​shǎo xīn​jī cái zuì​zhōng shuō​fú kè​hù qiān​xià hé​tong.

   He put in a lot of effort to finally convince the client to sign the contract.

   Source: Dong Chinese Dictionary