2 sentences

1. 他整天嘻嘻的，看起来没有任何烦恼。

   tā zhěng​tiān xī​xī de, kàn​qǐ​lai méi​yǒu​rèn​hé fán​nǎo.

   He's giggling all day and seems to have no worries at all.

   Source: Dong Chinese Dictionary

2. 她看着那张滑稽的照片，忍不住嘻嘻直笑。

   tā kàn zhe nà zhāng huá​jī de zhào​piàn, rěn bù zhù xī​xī zhí​xiào.

   Looking at that funny photo, she couldn't help giggling.

   Source: Dong Chinese Dictionary