2 sentences

1. 他这人性格太倔，一旦决定的事情谁也劝不动。

   tā zhè rén xìng​gé tài jué, yī​dàn jué​dìng de shì​qing shéi yě quàn bù dòng.

   He is so stubborn that once he makes up his mind, no one can talk him out of it.

   Source: Dong Chinese Dictionary

2. 老头子说话口气太倔，让几个年轻人都觉得很难堪。

   lǎo​tóu​zi shuō​huà kǒu​qì tài juè, ràng jǐ gè nián​qīng​rén dōu jué​de hěn nán​kān.

   The old man spoke in such a stubborn tone that it made several young people feel quite embarrassed.

   Source: Dong Chinese Dictionary