chuckle

The old man gave a soft chuckle as he watched the puppies playing.

(Chinese) 老人看着小狗玩耍，发出了轻柔的咯咯笑声。

She couldn't help but chuckle at the funny story her brother told.

(Chinese) 听了弟弟讲的有趣故事，她禁不住咯咯地笑了起来。