"I'm afraid it's going to rain tonight"
这句话来源于英语中“I'm afraid”这个短语，它表示“我担心”、“我害怕”之意。加上后面的“it's going to rain tonight”，就表示“我担心今晚要下雨”。
"I'm afraid it's going to rain tomorrow, so we'll have to cancel the picnic."
("我担心明天要下雨，所以我们不得不取消野餐。")
"I'm afraid the forecast says there's a high chance of rain this evening."
("我担心预报说今晚有很大可能下雨。")
"I'm afraid we're in for a rainy week, so make sure to pack an umbrella."
("我担心这个星期会下雨，所以一定要记得带雨伞。")