When asking this question you are inquiring how often or how frequent someone does a particular thing.

当你问这个问题的时候，你就是询问某人做一件特定事情的频次或频率。

Here are some examples: 这里有一些例子： 

"How often do you exercise?"

 你多久锻炼一次？

"How often do you change your password?"

 你多久改一次你的密码？

"How often do you help out at school?"

 你多久在学校帮一次忙？

"How often do you listen to your MP3 player?" 

你多久听一次你的MP3？

"How often do you need to go to the dentist?"

 你需要多久看一次牙医？

"How often do you receive your magazine in the mail?"

 在邮件中你多久收到一次你的杂志？

"How often do you report to your supervisor?"

 你多久向你的上司汇报工作？

"How often do you stretch before working out?"

 在锻炼之前你多久做一次伸展运动？

"How often do you talk to your parents?"

 你多久和父母聊一次？

"How often do you travel?"

 你多久旅游一次？