5:39用英语表达为 "five thirty-nine"。这是一种时间表达方式，由小时数和分钟数组合而成。小时数在前，分钟数在后，中间用冒号隔开。例如：
"I'll meet you at five thirty-nine." (我会在5:39见到你。)
"The train leaves at five thirty-nine in the morning." (火车早上5:39离站。)
"I'll call you back at five thirty-nine this evening." (我今晚5:39给你回电话。)