你学习英语多长时间了？ 这句翻译成英语是How long have you studying English?吗？能在you 后加been吗？

不是能不能。。是应该加。。
How long have you been studying English?
"study English"是个从过去开始并持续到现在的动作，应该用现在完成进行时。。
或者干脆是"How long have you studie（是studied哦，完成时的have hou 一定要跟动词的过去完成时的） English?"用现在完成时也可以。

必须的How long have you been studying English？
或者How long have you studied English？

how long have you studied english?
how long have you been studying english?
这两种表达都可以

译为How long have you been studying English?/How long have you studied English?
应该是have been doing 不能缺been

必须要加been，表示保持学英语这个状态studying

好像是How long have you been studying English ?现在完成时的基本结构是have /has +been+doing somgthing
好像就是这样了，呵呵！