I have been studying English for four years.就for four years提问

问题描述:

I have been studying English for four years.就for four years提问

How long have you been studying English?
how long 提问时间长短

How long have you been studying English for?

就 for 加时间段的短语的提问,应用表示时间段的疑问词进行提问
即:How long
所以句子应为:How long have you been studying English?

How long have you been studying English?