I have learned English for ten years中的learned为什么加ED

I have learned English for ten years中的learned为什么加ED i have learned english for 3 years.这里哪里错 改写句子 I have learned English for six years.It is six years __ 把下面句子改为被动句I have learned English for about two years English we have learned English (for)six years.括号中为什么填for I have learned English for eight years,I cant use it very we have learned English for about two years 的被动语态 we have learned english for 2 years?同义句! 同义句转换；I have learned English for five years.急! I [ ] English for three years 1.learn 2.learned 3.have learn 把下列句子改成被动语态：I have learned English for about two years How long have you learned English?I have learned English ()