2 sentences

1. 在这个领域，他纯粹是个外行。

   zài zhè​ge lǐng​yù, tā chún​cuì shì gè wài​háng.

   In this field, he is a complete layman.

   Source: Dong Chinese Dictionary

2. 这种做法太外行了，肯定会出错。

   zhè zhǒng zuò​fǎ tài wài​háng le, kěn​dìng huì chū​cuò.

   This approach is too amateurish; things are bound to go wrong.

   Source: Dong Chinese Dictionary