2 sentences

1. 大家都准时到了，单单他一个人迟到。

   dà​jiā dōu zhǔn​shí dào le, dān​dān tā yī gè rén chí​dào.

   Everyone arrived on time, except him alone, who was late.

   Source: Dong Chinese Dictionary

2. 他这么做单单是为了帮忙，别无他意。

   tā zhè​me zuò dān​dān shì wèi​le bāng​máng, bié wú tā yì.

   He did this solely to help, with no other intention.

   Source: Dong Chinese Dictionary