how often

• 用于询问频率或事件规律性的疑问短语。由副词“how”和“often”组成；与“times”“occasions”等名词连用时，整体作复杂的限定短语。

An interrogative phrase used to ask about frequency or regularity of events. Note: 'How often' is primarily an interrogative adverbial phrase consisting of 'how' + the adverb 'often'. When used before nouns like 'times', 'occasions', or 'intervals', it functions as a complex determiner phrase modifying those nouns. This entry focuses on its determiner-like usage with nominal complements.

1. Interrogative determiner (frequency with nouns)A2formal

   Used before nouns denoting occurrences or intervals (e.g., 'times', 'occasions', 'intervals') to ask about the rate or regularity of an event.

   疑问限定词（与名词搭配表示频率）

   • How often times do you check your email?
   • How often occasions does this error occur?
   • How often intervals should the equipment be serviced?

2. Adverbial usage (standalone frequency)A1informal

   Used without a following noun to ask about how frequently an action occurs. The noun is implied by context. (Note: This is the most common adverbial usage, included for completeness).

   副词用法（独立频率）

   • How often do you exercise?
   • How often does the bus come?
   • How often have you been to London?

3. Indirect question usageB1formal

   Used to introduce a noun clause that reports a question about frequency, functioning as the object of verbs like 'know', 'ask', 'wonder'.

   间接疑问用法

   • I wonder how often she practices.
   • Do you know how often this happens?
   • Tell me how often you visit them.

4. Exclamatory or emphatic useB2informal

   Used in exclamations or rhetorical questions to emphasize the surprising frequency or rarity of an event.

   感叹或强调用法

   • How often times I've told you this!
   • How often must I repeat myself?
   • How often do we get such an opportunity!