Privately, I think English is difficult because I'm not fluent in the subject vocabulary and conversation, either intentionally, but I think it is not difficult for English?
Personally, I think the course is difficult because my English is not fluent vocabulary and conversation. But after carefully studying English, I think it's not too hard.
Personally, I think English is difficult because I labored on vocabulary and conversation. But after studying carefully, I think English is not so difficult!