Men are subject to sudden changes of fortune as the moon is subject to the changes of being full and crescent, cloudy and clear.
人有旦夕祸福，月有阴晴圆缺。
The sky is cloudy, and looks like rain.
天空阴沉沉的，像是要下雨。
The room became cloudy with a blue haze of smoke.
蓝幽幽的烟使房间雾气腾腾。
This is a cup of cloudy water.
这是一杯混浊的水。
The weather is now clear, now cloudy.
天气一会儿晴一会儿阴。