Please check the following paragraph.
I have learned English for several years. I found English interesting for some resons. First, I can understand what the English words mean. Second, I can talk to foreigners in English. Third, I can also learn some foreign cultures. Therefore, I like learning English very much.
I have studied English for several years and have found it to be a very interesting experience. First, I have learned many English words. Next, it has helped me speak with foreign visitors. Finally, I have come to better understand other cultures.
(Please remember: we cannot say "I have learned X FOR SEVERAL YEARS."