I have been to Beijing three times.这句话对three times提问该用How often 还是How many times

how many times

how many times
多少次,不是频率.how often 问的是频率.

how many times
多少次,不是频率.how often 问的是频率.

用how many times来提问。
how often和how many times看起来比较容易混淆，可是具体分析一下用汉语就很明显了。
*how often 就频率提问 *how many times 是就次数提问
how often意为“多久……次、是否经常”，用来提问在某一特定的时间进行某个动作的次数，答语通常是always，usually，often，sometimes，once/twice a day/month等。
—How often do you get to school very early? 你多久早到校一次？
—Usually. 通常。

您好，很高兴为您解答。
I have been to Beijing three times.
意思是我已经去北京三次了。
How often 是问多久一次，问频率，显然不合题意， 而How many times 表示多少次，和题目吻合，故正确答案是：
How many times do you have been to Beijing?