The phrase "how often" in Hindi means "कितनी बार" (kitni baar). It is used to ask about the frequency of an action or event, essentially meaning "how many times" something happens or is done within a certain period. For example:

• "How often do you go there?" translates to "आप कितनी बार वहाँ जाते हैं?"
• "How often do you wash your hair?" translates to "आप अपने बालों को कितनी बार धोते हैं?"

In short, "how often" is used to inquire about the number of times or frequency something occurs and is commonly translated as "कितनी बार" in Hindi.