问一件事多久发生一次，先用 How often 开头，动作前面接 do / does（How often do you run?），表示感受的词前面接 is / are（How often are you tired?）。
How often + do / does
How often do you exercise?
How often does she visit?
How often do they play soccer?
试一试: ___ you go to the gym? (How often do / How often / How often are) 答案: How often do — 这个句型需要在 "How often" 后面加 do：How often do you go? 少了它（"How often you go?"）句子就不完整。
Not "How often does you cook?" — say "How often do you cook?". you 用 do。does 只留给 he、she、it。
试一试: How often ___ Amina visit her family? (does / do / is) 答案: does — Amina 是一个人（she），所以这里用 does：How often does Amina visit?（"do" 是给 you/we/they 用的。）
用频率来回答
要用多少次来回答，而不是某一天：every day、twice a week、usually、never。
How often do you exercise? Three times a week.
How often does she visit? Every weekend.
How often do they meet? Usually on Fridays.
Not "How often do you go? On Monday." — say "How often do you go? Every Monday.". "How often" 问的是次数，所以要用像 every Monday 这样的频率来回答。
试一试: How often do you play tennis? 选出自然的回答。 (Twice a week. / At the park. / Yes, I do.) 答案: Twice a week. — "How often" 问的是次数，所以要用频率来回答：Twice a week. "At the park" 回答的是地点；"Yes, I do" 回答的是是非问句。
用 do / does，不用 is / are
说到动作（go、work、eat）的时候，句型用 do / does。这里不要用 is / are。
How often do you travel?
How often does he call?
How often do they visit?
Not "How often you travel?" — say "How often do you travel?". 别漏掉 do。像 travel 这样的动作词，句型里要用 do，不是 is / are。
试一试: How often ___ you eat out? (do / are / is) 答案: do — 像 eat 这样的动作词需要 do：How often do you eat out? are 留给表示感受的词，比如 How often are you tired?
试一试: Ask about Hiroshi's habit. How often ___ he take the bus? (does / do / is) 答案: does — Hiroshi 是一个人（he），所以这里用 does：How often does he take the bus?（he/she/it → does。）
问多久一次
采访时，问别人的习惯要用 How often。先说 How often，再接 do 或 does，然后是问题的其余部分。
How often do you check your email?
How often does she answer the phone?
试一试: Interviewer: ___ you answer the phone at work? Camila: Many times every day. 选出采访者的问题。 (How often do / What time do / Where do) 答案: How often do — Camila 回答的是次数，每天很多次，所以问题要用 How often do：How often do you answer the phone? What time do 问的是几点，Where do 问的是地点，都跟她的回答对不上。
How often are you tired?（be）和 How often do you run?（动作）
看看表示人的词后面的词。如果是感受或描述，比如 tired，就保留 be：How often are you tired? 如果是动作，比如 run，就用 do 或 does：How often do you run?
How often are you tired? (a feeling, with are)
How often do you run? (an action, with do)
Not "How often do you tired?" — say "How often are you tired?". tired 是跟在 be 后面的感受，所以问句保留 are，不用 do。
试一试: Amina: Camila works nights. Lars: How often ___ she tired in the morning? 选出 Lars 要用的词。 (is / does) 答案: is — Camila 上夜班，所以早上她可能会觉得累。Tired 是跟在 be 后面的感受，所以问句要用 is：How often is she tired? does 要跟动作词搭配，不跟感受搭配。
试一试: Diego: Yasmin does not eat breakfast. Amina: How often ___ she hungry before lunch? 选出 Amina 要用的词。 (is / does) 答案: is — hungry 是跟在 be 后面的感受，所以问句要用 is，不用 does：How often is she hungry? does 要跟 walk 这样的动作词搭配。