2 sentences

1. 起先我以为她睡着了。

   qǐ​xiān wǒ yǐ​wéi tā shuì​zháo le.

   At first I thought she was asleep.

   Source: OpenSubtitles

2. 起先他并不同意，但后来改变了主意。

   qǐ​xiān tā bìng bù tóng​yì, dàn hòu​lái gǎi​biàn le zhǔ​yi.

   At first he didn't agree, but later he changed his mind.

   Source: Dong Chinese Dictionary