1. how long
指多長(zhǎng)時(shí)間，主要用來對(duì)一段時(shí)間(如three days, four weeks 等)提問：
How long ago was it? 這是多久前的事了?
How long do you think you’ll be gone? 你想你會(huì)離開多久?
How long have you known her? 你認(rèn)識(shí)她有多久了?
How long have you been studying the problem? 這問題你研究多久了？
“How long did he stay here?” “About two hours.” “他在這兒呆了多久?”“大約兩小時(shí)?！?BR> 2. how often
指每隔多久，主要用來對(duì)頻度副詞或狀語(如once a week等)提問：
How often does he come here? —Once a month. 他(每隔)多久來一次? —一每月一次。
How often do you visit your mother?一Once a week. 你多長(zhǎng)時(shí)間看你媽媽一次?——一周一次。
How often do you go to the dentist?一I go every six months. 你多久去看一次牙齒?——我每6個(gè)月去一次。
3. how soon
指再過多久，主要用來對(duì)表示將來的一段時(shí)間(如in an hour, in two weeks 等)提問：
How soon can you come? 你多快能趕來?
How soon shall we know the results? 一I don’t know. 我們多久能知道結(jié)果? ——我不知道。
How soon will he be back?—In an hour. 他要多久才回來?——1小時(shí)以后。
How soon will you be / have finished, dear? 親愛的，你還要多久才能準(zhǔn)備好呢?
How soon will you know your holiday dates? 你什么時(shí)候才能知道休假13期?
指多長(zhǎng)時(shí)間，主要用來對(duì)一段時(shí)間(如three days, four weeks 等)提問：
How long ago was it? 這是多久前的事了?
How long do you think you’ll be gone? 你想你會(huì)離開多久?
How long have you known her? 你認(rèn)識(shí)她有多久了?
How long have you been studying the problem? 這問題你研究多久了？
“How long did he stay here?” “About two hours.” “他在這兒呆了多久?”“大約兩小時(shí)?！?BR> 2. how often
指每隔多久，主要用來對(duì)頻度副詞或狀語(如once a week等)提問：
How often does he come here? —Once a month. 他(每隔)多久來一次? —一每月一次。
How often do you visit your mother?一Once a week. 你多長(zhǎng)時(shí)間看你媽媽一次?——一周一次。
How often do you go to the dentist?一I go every six months. 你多久去看一次牙齒?——我每6個(gè)月去一次。
3. how soon
指再過多久，主要用來對(duì)表示將來的一段時(shí)間(如in an hour, in two weeks 等)提問：
How soon can you come? 你多快能趕來?
How soon shall we know the results? 一I don’t know. 我們多久能知道結(jié)果? ——我不知道。
How soon will he be back?—In an hour. 他要多久才回來?——1小時(shí)以后。
How soon will you be / have finished, dear? 親愛的，你還要多久才能準(zhǔn)備好呢?
How soon will you know your holiday dates? 你什么時(shí)候才能知道休假13期?