They sometimes wrote letters last year.针对sometimes怎么提问
问题描述：
They sometimes wrote letters last year.针对sometimes怎么提问
答
How often did they write letters last year?
And what they usually talked about in the letter?
答
有时，偶尔
答
How often did they write letters last year?
问频率
用how often
答
how often did they write letters last year?