这三者都是时间频率的问题
howlong 只多久,一般情况指持续时间比较久的,如果指在某地住一段时间
How long have you lived that place? 3 years.
How often 指经常性的动作
How often do you go to the coffee shop within one week. 3 times a week
how soon 指马上要去做某事. 不是经常的,现在要去做的.
How soon you with catch it? Within 30 minutes.