how long, how often, how soon
how long指多長時間,主要用來對一段時間(如three days, four weeks 等)提問。
如:
How long ago was it? 這是多久前的事了?
how often指每隔多久,主要用來對頻率副詞或狀語(如once a week等)提問。如:
—How often does he come here? —Once a month. 他(每隔)多久來一次?每月一次?
how soon指再過多久,主要用來對表示將來的一段時間(in an hour, in two weeks 等)提問。
如:
How soon can you come? 你多快能趕來?