How often did you go to the concert this term?

sometimes
how often 就频率提问
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.
—How often do you see a film? 你多久看一次电影?
—Once a month. 每月一次.
如果是“how many times ”就次数提问,就选择twice