harbinger

The first snowdrop was a harbinger of spring, a promise of warmer days to come.第一朵雪花莲是春天的先兆，是对未来更温暖日子的承诺。

The appearance of the robin was a harbinger of change, a sign that things were about to shift.知更鸟的出现是变革的先兆，是一个即将发生转变的信号。